Nor indeed does the difference between prolific and unprolific or wind

eggs consist herein, that the former contained the seed of the male, as

Aldrovandus supposed; nor has it been noticed that anything has been

formed and coagulated in the egg by the seed of the male, nor has any

sensible transmutation been discovered (for indeed, there is no sensible

difference between the fertile and the wind egg); and yet a prolific

egg, conceived long after coition, has in itself the faculties of both

sexes; viz., the capability of being both formed itself, and of forming

a chick; as if, according to the idea of Aristotle, it had derived its

origin from the coition of the two, and their mutual endeavours towards

the same end; and compelled by the force of this argument, as mentioned

above, when speaking of the generation of the ovum, he has endowed the

egg with a vital principle (anima.) If such really exist, then, without

doubt it would be the origin and efficient of all the natural phenomena

which take place in the egg. For if we consider the structure of the

chick, displaying, as it does, so much art, so divine an intelligence

and foresight; when we see the eyes adapted for vision, the bill for

taking food, the feet for walking, the wings for flying, and similarly

the rest of its parts, each to its own end, we must conclude, whatever

the power be which creates such an animal out of an egg, that it is

either the soul, or part of the soul, or something having a soul, or

something existing previous to, and more excellent than the soul,

operating with intelligence and foresight.

From the generation of the chick, it is also manifest that, whatever may

have been its principle of life or first vegetative cause, this cause

itself first existed in the heart. Now, if this be the soul of the

chicken, it is equally clear, that that soul must have existed in the

punctum saliens and the blood; since we there discover motion and sense;

for the heart moves and leaps like an animal. But if a soul exists in

the punctum saliens, forming, nourishing, and augmenting the rest of the

body, in the manner which we have pointed out in our history, then it,

without doubt, flows from the heart, as from a fountain-head, into the

whole body. Likewise, if the existence of the vital principle (anima) in

the egg, or, as Aristotle supposes, if the vegetative part of the soul

be the cause of its fertility, it must follow that the punctum saliens,

or animate genital part, proceeds from the vital principle (anima) of

the egg, (for nothing is its own author,) and that the said vital

principle (anima) passes from the egg into the punctum saliens,

presently into the heart, and thence into the chick.

Moreover, if the egg have a prolific virtue, and a vegetative soul, by

which the chick is constructed, and if it owe them, as is allowed on all

hands, to the semen of the cock; it is clear that this semen is also

endowed with an active principle (anima.) For such is Aristotle’s

opinion, when he expresses himself as follows: “As to whether the semen

has a vital principle (anima) or not, the same reasoning must be adduced

which we have employed in the consideration of other parts. For no

active principle (anima) can exist, except in that thing whose vital

principle it is; nor can there be any part which is not partaker of the

vital principle, except it be equivocally, as the eye of a dead man. We

must, therefore, allow, both that the semen has an active principle

(anima) and is potential.”

Now from these premises, it follows that the male is the primary

efficient in which the ratio and forma reside, which produces a seed or

rather a prolific geniture, and imparts it, imbued as it is with an

anima vegetativa (with which also the rest of its parts are endowed) to

the female. The introduction of this geniture begets such a movement in

the material of the hen, that the production of an animate egg is the

result, and from thence too the first particle of the chick is animated,

and afterwards the whole chick. And so, according to Aristotle, either

the same soul passes, by means of some metempsychosis, from the cock

into his geniture, from the geniture into the material of the female,

thence into the egg, and from the egg into the chick; or else, it is

raised up in each of the subsequent things by its respective antecedent;

namely, in the seed of the male by the male himself, in the egg by the

seed, last in the chick by the egg, as light is derived from light.

The efficient, therefore, which we look for in the egg, to explain the

birth of the chick, is the vital principle (anima); and therefore, the

vital principle of the egg; for, according to Aristotle, a soul does not

exist except in that thing whose soul it is.

But it is manifest, that the seed of the male is not the efficient of

the chick; neither as an instrument capable of forming the chick by its

motion, as Aristotle would have it, nor as an animate substance

transferring its vitality (anima) to the chick. For in the egg there is

no semen, neither does any touch it, nor has ever done so; (“and it is

impossible that that which does not touch should move, or that anything

should be affected by that which does not move it,”) and therefore the

vitality of the semen ought not to be said to exist in it; and although

the vital principle may be the efficient in the egg, yet it would not

appear to result more from the cock or his semen, than from the hen.

Nor, indeed, is it transferred by any metempsychosis or translation from

the cock and his semen into the egg, and thence into the chick. For how

can this translation be carried on into the eggs that are yet to exist,

and to be conceived after intercourse? unless either some animate semen

be in the mean time working in some part of the hen; or the vital

principle only have been translated without the seed, in order to be

infused into any egg which might thereafter be produced; but neither of

these alternatives is true. For in no part of the hen is the semen to be

found; nor is it possible that the hen after coition should be possessed

of a double vital principle, to wit, her own, and that of the future

eggs and chicks; since “the living principle or soul is said to be

nowhere but in that thing whose soul it is,” much less can one or more

vital principles lie hidden in the hen, to be afterwards subservient to

the future eggs and chicks in their order, as they are produced.

We have adduced these passages out of Aristotle in order to set forth

his opinion of the manner in which the seed of the cock produces the

chick from the egg; and thereby throw at least some light on this

difficult question. But whereas the said passages do not explain the

mode in which this is accomplished, nor even solve the doubts proposed

by himself, it appears that we are still sticking in the same mud, and

caught in the same perplexities (concerning the efficient cause of the

fœtus in the generation of animals;) indeed, so far from Aristotle’s

arguments rendering this question more clear, they appear on the

contrary to involve it in more and greater doubts.

Wherefore it is no wonder that the most excellent philosopher was in

perplexity on this head, and that he has admitted so great a variety of

efficient causes, and at one time has been compelled to resort to

automatons, coagulation, art, instruments, and motions, for

illustrations; at another time to an ‘anima’ in the egg, and in the seed

of the male. Moreover, when he seems positively and definitively to

determine what it is in each seed, whether of plants or animals, which

render the same fertile, he repudiates heat and fire as improper agents;

nor does he admit any faculty of a similar quality; nor can he find

anything in the seed which should be fit for that office; but he is

driven to acknowledge something incorporeal, and coming from foreign

sources, which he supposes (like art, or the mind) to form the fœtus

with intelligence and foresight, and to institute and ordain all its

parts for its welfare. He takes refuge, I say, in a thing which is

obscure and not recognizable by us; namely, in a spirit contained in the

seed, and in a frothy body, and in the nature in that spirit,

corresponding in proportion to the elements of the stars. But what that

is, he has nowhere informed us.

EXERCISE THE FORTY-EIGHTH.

_The opinion of Fabricius on the efficient cause of the chick is

refuted._

As I have chosen Aristotle, the most eminent among the ancient

philosophers, and Fabricius of Aquapendente, one of the foremost

anatomists of modern times, as my especial guides and sources of

information on the subject of animal generation, when I find that I can

make nothing of Aristotle upon a particular topic, I straightway turn to

Fabricius; and now I desire to know what he thought of the efficient

cause of generation.

I find that he endeavours to satisfy three doubts or difficulties

involved in this subject: First, What is the ‘efficient’ of the chick?

This he answers, by saying, the semen of the male. Secondly, How does

this appear in the egg, and in what way does the semen of the cock

fecundate the egg? Thirdly and lastly, In what order are the parts of

the chick engendered?

As to the first query, it appears from our observations, that the cock

and his seminal fluid are verily the ‘efficient,’ but not the

‘adequate’ cause of generation; that the hen comes in here as something.

In this place, therefore, we are principally to inquire how the semen of

the cock fecundates the egg otherwise unprolific, and secures the

engenderment of a chick from it?

But let us hear Fabricius:[265] “Those things differ,” he observes,

“that are produced from eggs, from those that originate from semen, in

this, that oviparous animals have the matter from which the embryo is

incorporated distinct and separate from the agent; whilst viviparous

animals have the efficient cause and the matter associate and

concorporate. For the ‘agent’ in the oviparous animal is the semen of

the male, in the fowl the semen of the cock, which neither is nor can be

in the egg; the ‘matter,’ again, is the chalazæ from which the fœtus is

incorporated. These two differ widely from one another; for the chalazæ

are added after the vitellus is formed, whilst it is passing through the

second uterus, and are an accession to the internal egg; the semen

galli, on the contrary, is stored near the fundament, is separated from

the chalazæ by a great interval, and nevertheless by its irradiating

faculty, fecundates both the whole egg and the uterus. Now in the

viviparous animal, the semen is both ‘matter’ and ‘agent,’ the two

consisting and being conjoined in the same body.”

Our author appears to have introduced this distinction between oviparous

and viviparous animals, that he might spare, or at all events, that he

might not directly shock or upset the notions of medical writers on the

generation of man, they teaching that the seminal fluids of either sex,

projected together in intercourse, are mingled; that as one or other

preponderates, this becomes the ‘efficient,’ that stands in lieu of the

‘matter;’ and that the two together, tending to the same end, amalgamate

into the ‘conception’ of the viviparous animal.

But when he finds that neither in the egg nor uterus of the fowl is

there any semen or blood, and avows his belief that nothing is emitted

by the male in intercourse, that can by possibility reach the uterus of

the female, nor in the egg discovers a trace of aught supplied by the

male, he is compelled to doubt how the semen, which is nowhere to be

detected, which is neither mixed with the ‘geniture’ of the female, nor

yet is added to it, nor touches it, can fecundate the egg, or constitute

the chick. And this all the more urgently, when he has stated that a few

connections in the beginning of the season suffice to secure the

fecundity of all the eggs that will be laid in its course. For how

should it seem otherwise than impossible that from the semen galli

communicated in the spring, but now long vanished, lost or consumed, the

eggs that continue to be laid through the summer and autumn, should

still be rendered fruitful and fit to produce pullets?

It is that he may meet such a difficulty half way, that he coins the

difference which has been noticed. By way of bolstering up his views, he

farther adduces three additional considerations:--First, since the semen

galli is neither extant in the egg, nor was ever present in the uterus,

nor is added as ‘material cause’ as in viviparous animals, he has chosen

to make it resident for a whole year in the body of the hen. And then

that he may have a fit receptacle or storehouse for the fecundating

fluid, he finds a blind sac near the inlet to the uterus, in which he

says the cock deposits his semen, wherein, as in a treasury, it is

stored, and from which all the eggs are fecundated. Lastly, although the

semen in that bursa comes into contact neither with the uterus, nor the

egg, nor the ovary, whereby it might fecundate the egg, or secure the

generation of a chick, he says, nevertheless, that from thence, a

certain spiritual substance or irradiation penetrates to the egg,

fecundates its chalazæ, and from these produces a chick. By this

affirmation, however, he appears to support the opinion of Aristotle,

namely, that the female supplies the ‘matter’ in generation, the male

the ‘efficient force;’ and to oppose the postulate of medical writers

about the mixture of seminal fluids, for the sake of which,

nevertheless, as I have said, he seems to have laid down his distinction

between oviparous and viviparous animals. To give an air of greater

likelihood to this notion of his, he goes on to enumerate the changes

which the semen, not yet emitted, but laid up in the testes and vesiculæ

seminales of animals, occasions.

But besides the fact that all this does not bear upon the question, for

the principal element under discussion is, not how the semen galli

renders the egg prolific, but rather, how does the semen galli fashion

and construct the chick from the egg? Almost everything he adduces in

support of his view appears either false or open to suspicion, as is

obvious, from the facts stated in our history; for neither is the blind

cavity situated at the root of the uropygium or coccyx of the fowl,

which he entitles “bursa,” destined as a receptacle for the semen of the

cock, nor can any semen be discovered there, as we have said; but the

cavity is encountered in the male as well as in the female fowl.

Our authority nowhere explains what he understands by a “spiritual

substance,” and an “irradiation;” nor what he means by “a substance

through whose virtue the egg is vivified:” he does not say whether it is

any “corporeal” or “formal” substance, which by “irradiation” proceeds

from the semen laid up in the bursa, and, (what is especially required,)

constructs a pullet from the egg.

In my opinion, Fabricius does no more here than say: “It produces the

chick because it irradiates the egg; and forms because it vivifies;” he

attempts to explain or illustrate the exceedingly obscure subject of the

formation of a living being by means still more obscure. For the same

doubt remains untouched, how, to wit, the semen of the cock without

contact, an “external efficient” at best, separate in point of place,

and existing in the bursa, can form the internal parts of the fœtus in

ovo,--the heart, liver, lungs, intestines, &c., out of the chalazæ by

“irradiation.” Unless, indeed, our author will have it that all takes

place at the dictum as it were of a creator seated on his throne, and

speaking the words: Let such things be! namely, bones for support,

muscles for motion, special organs for sense, members for action,

viscera for concoction and the like, and all ordered for an end and

purpose with foresight, and understanding and art. But Fabricius nowhere

demonstrates that the semen has any such virtue, nowhere explains the

manner in which without so much as contact the semen can effect such

things; particularly when we see that the egg incubated by a bird of

another kind than that which laid it, or cherished in any other way, or

in dung, or in an oven, far from the bursa of the parent hen, is still

quickened and made to produce an embryo.

The same difficulty still remains, I say: how or in what way is the

semen of the cock the “efficient” of the chick? It is in no wise removed

by invoking the irradiation of a spiritual substance. For did we even

admit that the semen was stored in the bursa, and that it incorporated

the embryo from the chalazæ by metamorphosis and irradiation, we should

not be the less deeply immersed in the difficulty of accounting for the

formation of all the internal parts of the chick. But these notions have

already been sufficiently refuted by us.

Wherefore, in investigating the efficient cause of the chick, we must

look for it as inhering in the egg, not as concealed in the bursa; and

it must be such, that although the egg have long been laid, be miles

removed from the hen that produced it, and be set under another hen than

its parent, even under a bird of a different kind, such as a turkey or

guinea-fowl, or merely among hot sand or dung, or in an oven constructed

for the purpose, as is done in Egypt, it will still cause the egg to

produce a creature of the same species as its parents, like them, both

male and female, and if the parents were of different kinds, of a hybrid

species, and having a mixed resemblance.

The knot therefore remains untied, neither Aristotle nor Fabricius

having succeeded even in loosening it, namely: how the semen of the male

or of the cock forms a pullet from an egg, or is to be termed the

“efficient” of the chick, especially when it is neither present in, nor

in contact with, nor added to the egg. And although almost all assert

that the male and his semen are the efficient cause of the chick, still

it must be admitted, that no one has yet sufficiently explained how it

is so, particularly in our common hen’s egg.

EXERCISE THE FORTY-NINTH.

_The inquiry into the efficient cause of the chick is one of great

difficulty._

The discussion of the efficient cause of the chick is, as we have said,

sufficiently difficult, and all the more in consequence of the various

titles by which it has been designated. Aristotle, indeed, recites

several efficient causes of animals, and numerous controversies have

arisen on the subject among writers, (these having been particularly hot

between medical authors and Aristotelians,) who have come into the arena

with various explanations, both of the nature of the efficient cause and

of the mode of its operation.

And indeed the Omnipotent Creator is nowhere more conspicuous in his

works, nowhere is his divinity more loudly proclaimed, than in the

structure of animals. And though all know and admit that the offspring

derives its origin from male and female, that an egg is engendered by a

cock and a hen, and that a pullet proceeds from an egg, still we are not

informed either by the medical schools or the sagacious Aristotle, as to

the manner in which the cock or his semen fashions the chick from the

egg. For from what we have had occasion to say of the generation of

oviparous and other animals, it is sufficiently obvious that neither is

the opinion of the medical authorities admissible, who derive generation

from the admixture of the seminal fluids of the two sexes, nor that of

Aristotle, who holds the semen masculinum for the efficient, and the

menstrual blood for the material cause of procreation. For neither in

the act of intercourse nor shortly after it, is aught transferred to the

cavity of the uterus, from which as matter any part of the fœtus is

immediately constituted. Neither does the “geniture” proceeding from the

male in the act of union (whether it be animated or an inanimate

instrument) enter the uterus; neither is it attracted into this organ;

neither is it stored up within the fowl; but it is either dissipated or

escapes. Neither is there anything contained in the uterus immediately

after intercourse, which, proceeding from the male, or from the female,

or from both, can be regarded as the matter or rudiment of the future

fœtus. Neither is the semen galli stored and retained in the bursa

Fabricii of the hen or elsewhere, that from thence, as by the

irradiation of some spiritual substance, or by contact, the egg may be

fashioned or the chick constituted from the egg. Neither has the hen any

other semen save papulæ, yelks, and eggs. These observations of ours,

therefore, render the subject of generation one of greater difficulty

than ever, inasmuch as all the presumptions upon which the two old

opinions repose are totally overthrown. The fact is especial, as we

shall afterwards demonstrate, that all animals are alike engendered from

eggs; and in the act of intercourse, whether of man or the lower

quadrupeds, there is no seminal fluid, proceeding from the male or the

female, thrown into the uterus or attracted by this organ; there is

nothing to be discovered within its cavity, either before intercourse,

during the act, or immediately after it, which can be regarded as the

matter of the future fœtus, or as its efficient cause, or as its

commencement.

Daniel Sennert, a man of learning and a close observer of nature, having

first passed the reasonings of a host of others under review, approaches

the subject himself; and concludes that the vital principle inheres in

the semen and is almost identical with that which resides in the future

offspring. So that Sennert does not hesitate to aver that the rational

soul of man is present in his seminal fluid, and by a parity of

reasoning that the egg possesses the animating principle of the pullet;

that the vital principle is transported to the uterus of the female with

the semen of the male, and that from the seminal fluids of either

conjoined, not mixed (for mixture, he says, is applied to things of

different species), and endowed with soul or the vital principle a

perfect animal emerges. And therefore, he says, the semen of either

parent is required, whether to the constitution of the ovum or of the

embryo. And having said so much, he seems to think that he has overcome

all difficulties, and has delivered a certain and perspicuous truth.

But in order that we should concede a soul or vital principle (anima)

to the egg, and that combined from the souls of the parents, these being

occasionally of different species, the horse and the ass, the common

fowl and the pheasant, for example, this vital principle not being a

mixture but only an union; and allow the pullet to be produced in the

manner of the seeds of plants, by the same efficient principle by which

the perfect animal is afterwards preserved through the rest of its life,

so that it would be absurd to say that the fœtus grew by one vital

principle without the uterus or ovum, and by another within the uterus

or ovum--did we grant all this, I say (although it is invalid and

undeserving faith), our history of generation from the egg,

nevertheless, upsets the foundations of the doctrine, and shows it to be

entirely false; namely, that the egg is produced from the semen of the

cock and hen, or that any seminal fluid from either one or other is

carried to the uterus, or that the embryo or any particle of it is

fashioned from any seminal fluid transported to the uterus, or that the

semen galli, as efficient cause and plastic agent, is anywhere stored up

or reserved within the body of the hen to serve when attracted into the

uterus, as the matter and nourishment whence the fœtus which it has

produced should continue to grow. The conditions are wanting which he

himself admits, after Aristotle, to be necessary, viz., that the embryo

be constituted by that which is actual and preexists, and the chick by

that which is present and exists in the place where the chick is first

formed and increases; further, that it be produced by that which is

accomplished immediately and conjunctly, and is the same by which the

chick is preserved and grows through the whole of its life. For the

semen galli (and whether it is viewed as animate or inanimate is of no

moment) is nowise present and conjunct either in the egg or in the

uterus; neither in the matter from which the chick is fashioned, nor yet

in the chick itself already begun, and as contributing either to its

formation or perfection.

He dreams, too, when he seeks illustrations of his opinions on an

animated semen from such instances as the seeds of plants and acorns;

because he does not perceive the difference alleged by Aristotle[266]

between the “geniture” admitted in intercourse and the first conception

engendered by both parents; neither does he observe on the egg produced

originally in the cluster of the vitellarium, and without any geniture,

whether proceeding from the male or the female, translated to the

uterus. Neither does he understand that the uterus is, even after

intercourse, completely empty of matter of every kind, whether

transmitted by the parents, or produced by the intercourse, or

transmuted in any way whatever. Neither had he read, or at all events he

does not refer to the experiment of Fabricius, namely, that a hen is

rendered so prolific by a few treads of the cock, that she will continue

to lay fruitful eggs for the rest of the year, although in the interval

she receives no new accessions of semen for the fecundation of each egg

as it is laid, neither does she retain any of the seminal fluid which

she received so long ago.

So much is certain, and disputed by no one, that animals, all those at

least that proceed from the intercourse of male and female, are the

offspring of this intercourse, and that they are procreated as it seems

by a kind of contagion, much in the same way as medical men observe

contagious diseases, such as leprosy, lues venera, plague, phthisis, to

creep through the ranks of mortal men, and by mere extrinsic contact to

excite diseases similar to themselves in other bodies; nay, contact is

not necessary; a mere halitus or miasm suffices, and that at a distance

and by an inanimate medium, and with nothing sensibly altered: that is

to say, where the contagion first touches, there it generates an

“univocal” like itself, neither touching nor existing in fact, neither

being present nor conjunct, but solely because it formerly touched. Such

virtue and efficacy is found in contagions. And the same thing perchance

occurs in the generation of animals. For the eggs of fishes, which come

spontaneously to their full size extrinsically, and without any addition

of male seminal fluid, and are therefore indubitably possessed of

vitality without it, merely sprinkled and touched with the milt of the

male, produce young fishes. The semen of the male, I say, is not

intromitted in such wise as to perform the part of “agent” in each

particular egg, or to fashion the body, or to introduce vitality

(anima); the ova are only fecundated by a kind of contagion. Whence

Aristotle calls the milt of the male fish, or the genital fluid diffused

in water, at one time “the genital and fœtific fluid,” at another, “the

vital virus.” For he says[267]: “The male fish sprinkles the ova with

his genital semen, and from the ova that are touched by this vital virus

young fishes are engendered.”

Let it then be admitted as matter of certainty that the embryo is

produced by contagion. But a great difficulty immediately arises, when

we ask: how, in what way is this contagion the author of so great a

work? By what condition do parents through it engender offspring like

themselves, or how does the semen masculinum produce an “univocal” like

the male whence it flowed? When it disappears after the contact, and is

naught in act ulteriorly, either by virtue of contact or presence, but

is corrupt and has become a nonentity, how, I ask, does a nonentity act?

How does a thing which is not in contact fashion another thing like

itself? How does a thing which is dead itself impart life to something

else, and that only because at a former period it was in contact?

For the reasoning of Aristotle[268] appears to be false, or at all

events defective, where he contends “That generation cannot take place

without an active and a passive principle; and that those things can

neither act nor prove passive which do not touch; but that those things

come into mutual contact which, whilst they are of different sizes, and

are in different places, have their extremes together.”

But when it clearly appears that contagion from noncontingents, and

things not having their extremities together, produce ill effects on

animals, wherefore should not the same law avail in respect of their

life and generation? There is an “efficient” in the egg which, by its

plastic virtue (for the male has only touched though he no longer

touches, nor are there any extremes together), produces and fashions the

fœtus in its kind and likeness. And through so many media or instruments

is this power, the agent of fecundity, transmitted or required that

neither by any movement of instruments as in works of art, nor by the

instance of the automaton quoted by Aristotle, nor of our clocks, nor of

the kingdom in which the mandate of the sovereign is everywhere of

avail, nor yet by the introduction of a vital principle or soul into

the semen or “geniture,” can the aforementioned doctrine be defended.

And hence have arisen all the controversies and problems concerning the

attraction of the magnet and of amber; on sympathy and antipathy; on

poisons and the contagion of pestilential diseases; on alexipharmics and

medicines which prove curative or injurious through some hidden or

rather unknown property, all of which seem to come into play

independently of contact. And above all on what it is in generation

which, in virtue of a momentary contact--nay, not even of contact, save

through several media--forms the parts of the chick from the egg by

epigenesis in a certain order, and produces an “univocal” and like

itself, and that entirely because it was in contact at a former period.

How, I ask again, does that which is not present, and which only enjoyed

extrinsic contact, come to constitute and order all the members of the

chick in the egg exposed without the body of the parent, and often at a

long interval after it is laid? how does it confer life or soul, and a

species compounded of those of the concurring generants? Inasmuch as

nothing, it seems, can reproduce itself in another’s likeness.

EXERCISE THE FIFTIETH.

_Of the efficient cause of animals, and its conditions._

That we may proceed in our subject, therefore, and penetrate so far into

the knowledge of the efficient cause of animal generation as seems

needful in this place, we must begin by observing what instruments or

media are devoted to it. And here we come at once to the distinction

into male and female; seminal fluid and ovum, and its primordium. For

some males, as well as some females, are barren, or but little prolific;

and the seed of the male is at one time more, at another time less

prolific; because the semen masculinum stored up in the vesiculæ

seminales is esteemed unfruitful, unless it is raised into froth by the

spirits and ejected with force. And even then perchance it is not

endowed with equal fecundating force at all times. Neither are all the

germs of yelks in the ovary, nor all the eggs in the uterus made fertile

at the same instant.

Now I call that fruitful which, unless impeded by some extrinsic cause,

attains by its inherent force to its destined end, and brings about the

consequence for the sake of which it is ordained. Thus the cock is

called fruitful which has his hens more frequently and surely pregnant,

the eggs they lay being at the same time perfect and proper for

incubation.

The hen in like manner is esteemed fruitful which has the faculty of

producing eggs, or of receiving and long retaining the virtue of

prolific conception from the cock. The cluster of germs and the ovary

itself are regarded as prolific when the germs are numerous and of good

size.

The egg in the same way is fruitful which differs from a subventaneous

or hypenemic egg, and which, cherished by incubation, or in any other

way, does not fail to produce a chick.

Such an efficient cause consequently is required for the chick, as shall

impart the virtue of fecundity to it, and secure it the power of acting

as an efficient cause in its turn. Because that, or its analogue at

least, by means of which they become prolific, is present in all

animals. And the inquiry is the same in each case, when we ask what it

is in the egg which renders it prolific, and distinguishes it from a

wind egg; what in the vitellary germ and ovary; what in the female;

what, finally, in the semen and the cock himself? What, moreover, it is

in the blood and punctum saliens, or first formed particle of the chick,

whence all the other parts arise with their appropriate structures and

arrangements; what in the embryo or chick itself whereby it becomes more

or less robust and agile, attains to maturity with greater or less

rapidity, and lives with various degrees of health, for a longer or

shorter period?

Nor is the inquiry very different which goes to ascertain what sex the

male and the female, or the cock and the hen, confer upon the prolific

egg; and what proceeds from each that contributes to the perfection or

resemblance of the chick, viz., whether the egg, the conception, the

matter, and the nutriment proceed from the mother, and the plastic

virtue from the father; or rather a certain contagion immitted during

intercourse, or produced and received from him, which in the body of the

hen, or in the eggs, either permanently excites the matter of the eggs,

or attracts nourishment from the female, and concocts and distributes it

first for the growth of the eggs, and then for the production of the

chicks; finally, whether from the male proceeds all that has reference

to form and life and fecundity, from the female, again, all that is of

matter, constitution, place, and nourishment? For among animals where

the sexes are distinct, matters are so arranged, that since the female

alone is inadequate to engender an embryo and to nourish and protect the

young, a male is associated with her by nature, as the superior and more

worthy progenitor, as the consort of her labour, and the means of

supplying her deficiencies; in the case of the hen, of correcting by his

contagion the inferiority of the hypenemic eggs which she produces, and

so rendering them prolific. For as the pullet, engendered of an egg, is

indebted to that egg for his body, vitality, and principal or generative

part, so and in like manner does the egg receive all that is in it from

the female, the female in her turn being dependent on the male for her

fecundity which is conferred in coition.

And here we have an opportunity of inquiring, whether the male be the

first and principal cause of the generation of the offspring; or whether

the male along with the female are the mediate and instrumental causes

of nature itself, or of the first and supreme generator? And such an

inquiry is both becoming and necessary, for perfect science of every

kind depends on a knowledge of causes. To the full understanding of

generation, therefore, it is incumbent on us to mount from the final to

the first and supreme efficient cause, and to hold each and every cause

in especial regard.

We shall have occasion to define that which is the first and supreme

efficient cause of the chick in ovo by and by, when we treat of that

which constitutes the efficient cause [of generation] among animals in

general. Here, meantime, we shall see what its nature may be.

The first condition, then, of the primary efficient cause of generation,

properly so called, is, as we have said, that it be the prime and

principal fertilizer, whence all mediate causes receive the fecundity

imparted. For example, the chick is derived from the punctum saliens in

the egg, not only as regards the body, but also, and this especially, as

respects the life (anima): the punctum saliens, or heart, is derived

from the egg, the egg from the hen, and the hen has her fecundity from

the cock.

Another condition of the prime efficient is discovered from the work

achieved, viz., the chick, because that is the prime efficient in which

the reason of the effect is principally displayed. But since every

generative efficient engenders another like itself, and the offspring is

of a mixed nature, the prime efficient must also be a certain mixed

something.

Now, I maintain that the offspring is of a mixed nature, inasmuch as a

mixture of both parents appears plainly in it, in the form and

lineaments, and each particular part of its body, in its colour,

mother-marks, disposition to diseases, and other accidents. In mental

constitution, also, and its manifestations, such as manners, docility,

voice, and gait, a similar temperament is discoverable. For as we say of

a certain mixture, that it is composed of elements, because their

qualities or virtues, such as heat, cold, dryness, and moisture, are

there discovered associated in a certain similar compound body, so, in

like manner, the work of the father and mother is to be discerned both

in the body and mental character of the offspring, and in all else that

follows or accompanies temperament. In the mule, for instance, the body

and disposition, the temper and voice, of both parents (of the horse and

the ass, _e. g._) are mingled; and so, also, in the hybrid between the

pheasant and the fowl, in that between the wolf and the dog, &c.,

corresponding traits are conspicuous.

When, therefore, the chick shows his resemblance to both parents, and is

a mixed effect, the primary genital cause (which it resembles) must

needs be mixed. Wherefore that which fashions the chick in the egg is of

a mixed nature, a certain something mixed or compounded, and the work of

both parents. And if any kind of contagion, engendered under the

influence of sexual intercourse, in which the male and female mingle and

form but one body, either originates or remains in the body of the

female, that, too, must be of a mixed nature or power, whence,

subsequently, a fertile egg will be produced, endowed with plastic

powers, the consequence of a mixed nature, or of a mixed efficient

instrument, from which a chick, also of a mixed nature, will be

produced.

I have used the word _contagion_ above, because Aristotle’s view is

contradicted by all experience, viz., that a certain part of the embryo

is immediately made by intercourse. Neither is it true, as some of the

moderns assert, that the vital principle (anima) of the future chick is

present in the egg; for that cannot be the vital principle of the chick

which inheres in no part of its body. Neither can the living principle

be said either to be left or to be originated by intercourse; otherwise

in every pregnant woman there would be two vital principles (animæ)

present. Wherefore, until it shall have been determined what the

efficient cause of the egg is, what it is of mixed nature that must

remain immediately upon intercourse, we may be permitted to speak of it

under the title of a Contagion.

But where this contagion lies hid in the female after intercourse, and

how it is communicated and given to the egg, demands quite a special

inquiry, and we shall have occasion to treat of the matter when we come

to discuss the conception of females in general. It will suffice,

meantime, if we say that the same law applies to the prime efficient--in

which inheres the reason of the future offspring--as to the offspring;

as this is of a mixed nature, the nature of its cause must also be

mixed; and it must either proceed equally from both parents, or from

something else which is employed by both concurrently as instruments,

animated, co-operating, mixed, and in the sexual act coalescing unto

one. And this is the third condition of the prime efficient, that it

either imparts motion to all the intermediate instruments in succession,

or uses them in some other way, but comes not itself into play. Whence

the origin of the doubt that has arisen, whether, in the generation of

the chick, the cock were the true prime efficient, or whether there were

not another prior, superior to him? For, indeed, all things seem to

derive their origin from a celestial influence, and to follow the

movements of the sun and moon. But we shall be able to speak more

positively of this matter after we have shown what we understand by the

“instrument,” or “instrumental efficient cause,” and how it is

subdivided.

Instrumental efficients, then, are of different kinds: some, according

to Aristotle, are factive, others active; some have no capacity any way

unless conjoined with another prior efficient, as the hand, foot,

genital organs, &c. with the rest of the body; others have an influence

even when separate and distinct, as the seminal fluid and the ovum. Some

instruments, again, have neither motion nor action beyond those that are

imparted to them by the prime efficient; and others have peculiar

inherent principles of action, to which nature indeed allows no motion

in the business of generation, though she still uses their faculties,

and prescribes them laws or limits in their operations, not otherwise

than the cook makes use of fire in cooking, and the physician of herbs

and drugs in curing diseases.

Sennert, that he may uphold the opinion he had espoused of the vital

principle (anima) being present in the semen, and the formative faculty

of the chick being extant in the egg, asserts that not only is the egg,

but the semen of the cock, endowed with the living principle of the

future chick. Moreover, he distinctly denies that there is any separate

instrumental efficient; and says, that that only ought to be entitled

“instrument” which is conjoined with the prime efficient; and that only

“instrumental efficient,” which has no motion or action save that which

is imparted to it by the prime efficient, or which is continuously and

successively received, and in virtue of which it acts. And on this

ground he rejects the example of projectiles, which have received force

from the projecting agent, and, separated from it, act nevertheless; as

if swords and spears were properly to be called warlike weapons, but

arrows and bullets to be refused this title. He also rejects the

argument derived from the republic, denying thereby that magistrates,

counsellors, or ministers, are instruments of government; although

Aristotle regards a counsel as an efficient, and in express terms calls

a minister an instrument.[269] Sennert likewise denies the example of

automata; and says and gainsays much besides, with a view to confirming

himself in his position, that the semen and the egg are possessed of a

living principle (anima), and are not mediate or instrumental, but

principal agents. Sennert, nevertheless, as it were compelled by the

force of truth, lays down such conditions for a principal agent, as

fully and effectually contradict all that he had said before. He tells

us, for instance, that “whatever produces a work or an effect more noble

than itself, or an effect unlike itself, is not a principal efficient,

but an instrumental cause;” granting which, who would not infer that the

semen and the egg were instruments? seeing that the pullet is an effect

more noble than the egg, and every way unlike either this or the

spermatic fluid. Wherefore, when the learned Sennert denies the semen

and the egg to be instruments or organs, because they are distinct from

the prime agents, he takes his position upon a false basis; because, as

the prime generator procreates offspring by various means or media, the

medium being here conjunct, as the hand of the workman is with his body,

there separate and distinct, as is the arrow let loose from the bow, it

is still to be regarded as an instrument.

From the conditions now enumerated of an instrumental cause, it seems to

follow that the prime efficient in the generation of the chick is the

cock, or, at all events, the cock and hen, because the resulting pullet

resembles these; nor can it be held more noble than they, which are its

prime efficients or parents. I shall, therefore, add another condition

of the prime efficient, whence it may, perhaps, appear that the male is

not the prime, but only the instrumental, cause of the chick; viz., that

the prime efficient in the formation of the chick makes use of artifice,

and foresight, and wisdom, and goodness, and intelligence, which far

surpass the powers of our rational soul to comprehend, inasmuch as all

things are disposed and perfected in harmony with the purpose of the

future work, and that there be action to a determinate end; so that

every, even the smallest, part of the chick is fashioned for the sake of

a special use and end, and with respect not merely to the rearing of the

fabric, but also to its well-being, and elegance and preservation. But

the male or his semen is not such either in the act of kind or after it,

that art, intelligence, and foresight can be ascribed to him or it.

The proper inference from these premises appears to be that the male, as

well as his seminal fluid, is the efficient instrument; and the female

not less than the egg she lays the same. Wherefore, we have to seek

refuge in a prior, superior, and more excellent cause, to which, with

all propriety, are ascribed foresight, intelligence, goodness, and

skill, and which is by so much more excellent than its effect or work,

as the architect is more worthy than the pile he rears, as the king is

more exalted than his minister, as the workman is better than his hands

or tools.

The male and female, therefore, will come to be regarded as merely the

efficient instruments, subservient in all respects to the Supreme

Creator, or father of all things. In this sense, consequently, it is

well said that the sun and moon engender man; because, with the advent

and secession of the sun, come spring and autumn, seasons which mostly

correspond with the generation and decay of animated beings. So that the

great leader in philosophy says:[270] “The first motion [of the sphere?]

is not the cause of generation and destruction; it is the motion of the

ecliptic that is so, this being both continuous and having two

movements; for, if future generation and corruption are to be eternal,

it is necessary that something likewise move eternally, that

interchanges do not fail, that of the two actions one only do not occur.

The cause of the perpetuity [of animal species?] is, therefore, the law

of the universe; and the obliquity [of the ecliptic?] is the cause of

the approach and accession, [of the sun?] and of his being now nearer,

now more remote: when he quits us, and removes to a distance, it is then

that decay and corruption intervene; and, in like manner, when he

approaches, it is then that he engenders; and if, as he frequently

approaches, he engenders; so, because he frequently recedes, does he

cause corruption; for the causes of contraries are contrary.”

All things, therefore, grow and flourish in spring, (on the approach of

the sun, that is to say, he being the common parent and producer, or at

all events the immediate and universal instrument of the Creator in the

work of reproduction); and this is true not of plants only but of

animals also; nor less of those that come spontaneously, than of those

that are propagated by the consentient act of male and female. It is as

if, with the advent of this glorious luminary, Venus the bountiful

descended from heaven, waited on by Cupid and a cohort of graces, and

prompted all living things by the bland incitement of love to secure

the perpetuity of their kinds. Or (and it is thus that we have it in the

mythology) it is as if the genital organs of Saturn, cast into the sea

at this season, raised a foam, whence sprung Aphrodite. For, in the

generation of animals, as the poet says, “superat tener omnibus

humor,”--a gentle moisture all pervades,--and the genitals froth and are

replete with semen.

The cock and the hen are especially fertile in the spring; as if the

sun, or heaven, or nature, or the soul of the world, or the omnipotent

God--for all these names signify the same thing--were a cause in

generation superior and more divine than they; and thus it is that the

sun and man, i.e. the sun through man as the instrument, engender man.

In the same way the preserver of all things, and the male among birds,

give birth to the egg, from whence the chick, the perfect bird, is made

eternal in its kind by the approach and recession of the god of day,

who, by the divine will and pleasure, or by fate, serves for the

generation of all that lives.

Let us conclude, therefore, that the male, although a prior and more

excellent efficient than the female, is still no more than an

instrumental efficient, and that he, not less than the female, must

refer his fecundity or faculty of engendering as received from the

approaching sun; and, consequently, that the skill and foresight, which

are apparent in his work, are not to be held as proceeding from him but

from God; inasmuch as the male in the act of kind neither uses counsel

nor understanding; neither does man engender the rational part of his

soul, but only the vegetative faculty; which is not regarded as any

principal or more divine faculty of the soul, but one only of a lower

order.

Since, then, there is not less of skill and prescience manifested in the

structure of the chick than in the creation of man and the universe at

large, it is imperative even in the generation of man to admit an

efficient cause, superior to, and more excellent than man himself:

otherwise the vegetative faculty, or that part of the soul or living

principle which fashions and preserves a man, would have to be accounted

far more excellent and divine, and held to bear a closer resemblance to

God than the rational portion of the soul, whose excellence,

nevertheless, we extol over all the faculties of all animals, and esteem

as that which has right and empire in them, and to which all created

things are made subservient. Or we should else have to own that in the

works of nature there was neither prudence, nor art, nor understanding;

but that these appeared to us, who are wont to judge of the divine

things of nature after our own poor arts and faculties, or to contrast

them with examples due to ourselves; as if the active principles of

nature produced their effects in the same way as we are used to produce

our artificial works, by counsel, to wit, or discipline acquired through

the mind or understanding.

But nature, the principle of motion and rest in all things in which it

inheres, and the vegetative soul, the prime efficient cause of all

generation, move by no acquired faculty which might be designated by the

title of skill or foresight, as in our undertakings; but operate in

conformity with determinate laws like fate or special commandments--in

the same way and manner as light things rise and heavy things descend.

The vegetative faculty of parents, to wit, engenders in the same way,

and the semen finally arrives at the form of the fœtus, as the spider

weaves her web, as birds build nests, incubate their eggs, and cherish

their young, or as bees and ants construct dwellings, and lay up stores

for their future wants; all of which is done naturally and from a

connate genius or disposition; by no means from forecast, instruction,

or reason. That which in us is the principle or cause of artificial

operations, and is called art, intellect, or foresight, in the natural

operations of the lower animals is nature, which is ἀυτοδίδακτος,

self-taught, instilled by no one; what in them is innate or connate, is

with us acquired. On this account it is, that they who refer all to art

and artifice are to be held indifferent judges of nature or natural

things; and, indeed, it is wiser to act in the opposite way, and

selecting standards in nature to judge of things made by art according

to them. For all the arts are but imitations of nature in one way or

another; as our reason or understanding is a derivative from the Divine

intelligence, manifested in his works; and when perfected by habit, like

another adventitious and acquired soul, gaining some semblance of the

Supreme and Divine agent, it produces somewhat similar effects.

Wherefore, according to my opinion, he takes the right and pious view of

the matter, who derives all generation from the same eternal and

omnipotent Deity, on whose nod the universe itself depends. Nor do I

think that we are greatly to dispute about the name by which this first

agent is to be called or worshipped; whether it be God, Nature, or the

Soul of the universe,--whatever the name employed,--all still intend by

it that which is the beginning and the end of all things; which exists

from eternity and is almighty; which is author or creator, and, by means

of changing generations, the preserver and perpetuator of the fleeting

things of mortal life; which is omnipresent, not less in the single and

several operations of natural things, than in the infinite universe;

which, by his deity or providence, his art and mind divine, engenders

all things, whether they arise spontaneously without any adequate

efficient, or are the work of male and female associated together, or of

a single sex, or of other intermediate instruments, here more numerous,

there fewer, whether they be univocal, or are equivocally or

accidentally produced: all natural bodies are both the work and the

instruments of that Supreme Good, some of them being mere natural

bodies, such as heat, spirit, air, the temperature of the air, matters

in putrefaction, &c., or they are at once natural and animated bodies;

for he also makes use of the motions, or forces, or vital principles of

animals in some certain way, to the perfection of the universe and the

procreation of the several kinds of animated beings.

From what has now been said, we are apprized to a certain extent of the

share which the male has in the business of generation. The cock confers

that upon the egg, which, from unprolific, makes it prolific, this being

identical with that which the fruit of vegetables receives from the

fervour of the summer sun, which secures to them maturity, and to their

seeds fertility; and not different from that which fertilizes things

spontaneously engendered, and brings caterpillars from worms, aurelias

from caterpillars, from aurelias moths, butterflies, bees, &c.

In this way is the sun, by his approach, both the beginning of motion

and transmutation in the coming fruit, and the end, also, inasmuch as he

is the author of the fertility of its included seed: and, as early

spring is the prime efficient of leaves and flowers and fruits, so is

summer, in its strength, the cause of final perfection in the ripeness

and fecundity of the seed. With a view to strengthen this position, I

shall add this one from among a large number of observations. Some

persons in these countries cultivate orange trees with singular care and

economy, and the fruit of these trees, which, in the course of the first

year, will grow to the size of the point of the thumb, comes to maturity

the following summer. This fruit is perfect in all respects, save and

except that it is without pips or seeds.

Pondering upon this with myself, I thought that I had here an example of

the barren egg, which is produced by the hen without the concurrence of

the cock, and which comprises everything that is visible in a fruitful

egg, but is still destitute of germinant seed; as if it were the same

thing that was imparted by the cock, in virtue of which a wind-egg

becomes a fruitful egg, which in warmer countries is dispensed by the

sun, and causes the fruit of the orange tree to be produced replete with

prolific seed. It is as if the summer in England sufficed for the

production of the fruit only, as the hen for the production of the egg,

but like the female fowl was impotent as a pro-genetrix; whilst in other

countries enjoying the sun’s light in larger proportion, the summer

acquired the characters of the male, and perfected the work of

generation.

Thus far have we treated this subject by the way, that, from the

instance of the egg, we might learn what conditions were required in the

prime efficient in the generation of animals;--for it is certain, that

in the egg there is an agent,--as there is also in every conception and

germ,--which is not merely infused by the mother, but is first

communicated in coitu by the father, by means of his spermatic fluid;

and which is itself primarily endowed with such virtue by heaven and the

sun, or the Supreme Creator. It is equally manifest, that this agent,

existing in every egg and seed, is so imbued with the qualities of the

parents, that it builds up the offspring in their likeness, not in its

own; and this mingled also as proceeding from both united in copulation.

Now, as all this proceeds with the most consummate foresight and

intelligence, the presence of the Deity therein is clearly proclaimed.

But we shall have to speak at greater length upon this subject, when we

strive to show what it is that remains with the female immediately after

intercourse, and where it is stored; at the same time that we

explain--since there is nothing visible in the cavity of the uterus

after intercourse--what that prolific contagion or prime conception is;

whether it is corporeal and laid up within the female, or is

incorporeal; whether the conception of the uterus be of the same nature

or not with the conceptions of the brain, and fecundity be acquired in

the same way as knowledge--a conclusion, in favour of which there is no

lack of arguments; or, as motion and the animal operations, which we

call appetites, derive their origin from the conceptions of the brain,

may not the natural motions and the operations of the vegetative

principle, and particularly generation, depend on the conception of the

uterus? And then we have to inquire how this prolific contagion is of a

mixed nature, and is imparted by the male to the female, and by her is

transferred to the ovum? Finally, how the contagious principle of all

diseases and preternatural affections spreads insensibly, and is

propagated?

EXERCISE THE FIFTY-FIRST.

_Of the order of generation; and, first, of the primary genital

particle._

It will be our business, by and by, when we come to treat of the matter

in especial, to show what happens to the female from a fruitful embrace;

what it is that remains with her after this, and which we have still

spoken of under the name of contagion, by which, as by a kind of

infection, she conceives, and an embryo subsequently begins to grow of

its own accord. Meantime, we shall discourse of those things that

manifestly appear in connexion with the organs of generation which seem

most worthy of particular comment.

And first, since it appears certain that the chick is produced by

epigenesis, or addition of the parts that successively arise, we shall

inquire what part is formed first, before any of the rest appear, and

what may be observed of this and its particular mode of generation.

What Aristotle[271] says of the generation of the more perfect animals,

is confirmed and made manifest by all that passes in the egg, viz.: that

all the parts are not formed at once and together, but in succession,

one after another; and that there first exists a particular genital

particle, in virtue of which, as from a beginning, all the other parts

proceed. As in the seeds of plants, in beans and acorns, to quote

particular instances, we see the gemmula or apex, protruding, the

commencement of the entire prospective herb or tree. “And this particle

is like a child emancipated, placed independently, a principle existing

of itself, from whence the series of members is subsequently thrown out,

and to which belongs all that is to conduce to the perfection of the

future animal.”[272] Since, therefore, “No part engenders itself, but,

after it is engendered, concurs in its own growth, it is indispensable

that the part first arise which contains within itself the principle of

increase; for whether it be a plant or an animal, still has it within

itself the power of vegetation or nutrition;”[273] and at the same time

distinguishes and fashions each particular part in its several order;

and hence, in this same primogenate particle, there is a primary vital

principle inherent, which is the author and original of sense and

motion, and every manifestation of life.

That, therefore, is the principal particle whence vital spirit and

native heat accrue to all other parts, in which the calidum innatum sive

implantatum of physicians first shows itself, and the household deity or

perennial fire is maintained; whence life proceeds to the body in

general, and to each of its parts in particular; whence nourishment,

growth, aid, and solace flow; lastly, where life first begins in the

being that is born, and last fails in that which dies.

All this is certainly true as regards the first engendered part, and

appears manifestly in the formation of the chick from the egg. I am

therefore of opinion that we are to reject the views of certain

physicians, indifferent philosophers, who will have it that three

principal and primogenate parts arise together, viz.: the brain, the

heart, and the liver; neither can I agree with Aristotle himself, who

maintains that the heart is the first engendered and animated part; for

I think that the privilege of priority belongs to the blood alone; the

blood being that which is first seen of the newly engendered being, not

only in the chick in ovo, but in the embryo of every animal whatsoever,

as shall plainly be made to appear at a later stage of our inquiry.

There appears at first, I say, a red-coloured pulsating point or

vesicle, with lines or canals extending from it, containing blood in

their interior, and, in so far as we are enabled to perceive from the

most careful examination, the blood is produced before the punctum

saliens is formed, and is farther endowed with vital heat before it is

put in motion by a pulse; so that as pulsation commences in it and from

it, so, in the last struggle of mortal agony, does motion also end

there. I have indeed ascertained by numerous experiments instituted upon

the egg, as well as upon other subjects, that the blood is the element

of the body in which, so long as the vital heat has not entirely

departed, the power of returning to life is continued.

And since the pulsating vesicle and the sanguineous tubes extending

thence are visible before anything else, I hold it as consonant with

reason to believe that the blood is prior to its receptacles, the thing

contained, to wit, to its container, inasmuch as this is made

subservient to that. The vascular ramifications and the veins,

therefore, after these the pulsating vesicle, and, finally, the heart,

as being every one of them organs destined to receive and contain the

blood, are, in all likelihood, constructed for the express purpose of

impelling and distributing it, and the blood is, consequently, the

principal portion of the body.

This conclusion is favoured by numerous observations; particularly by

the fact that some animals, and these red-blooded, too, live for long

periods without any pulse; some even lie concealed through the whole

winter, and yet escape alive, though their heart had ceased from motion

of every kind, and their lungs no longer played; they had lain in fact

like those who lie half dead in a state of asphyxia from syncope,

leipothymia, or the hysterical passion.

Emboldened by what I have observed both in studying the egg, and whilst

engaged in the dissection of living animals, I maintain, against

Aristotle, that the blood is the prime part that is engendered, and the

heart the mere organ destined for its circulation. The function of the

heart is the propulsion of the blood, as clearly appears in all animals

furnished with red blood; and the office of the pulsating vesicle in the

generation of the chick ab ovo, as well as in the embryos of mammiferous

animals, is not different, a fact which I have repeatedly demonstrated

to others, showing the vesicula pulsans as a feeble glancing spark,

contracting in its action, now forcing out the blood which was contained

in it, and again relaxing and receiving a fresh supply.

The supremacy of the blood farther appears from this, that the pulse is

derived from it; for, as there are two parts in a pulsation, viz.:

distension or relaxation, and contraction, or diastole and systole, and,

as distension is the prior of these two motions, it is manifest that

this motion proceeds from the blood; the contraction, again, from the

vesicula pulsans of the embryo in ovo, from the heart in the pullet, in

virtue of its own fibres, as an instrument destined for this particular

end. Certain it is, that the vesicle in question, as also the auricle of

the heart at a later period, whence the pulsation begins, is excited to

the motion of contraction by the distending blood. The diastole, I say,

takes place from the blood swelling, as it were, in consequence of

containing an inherent spirit, so that the opinion of Aristotle in

regard to the pulsation of the heart,--namely, that it takes place by a

kind of ebullition,--is not without some mixture of truth; for what we

witness every day in milk heated over the fire, and in beer that is

brisk with fermentation, comes into play in the pulse of the heart; in

which the blood, swelling with a sort of fermentation, is alternately

distended and repressed; the same thing that takes place in the liquids

mentioned through an external agent, namely adventitious heat, is

effected in the blood by an intimate heat, or an innate spirit; and

this, too, is regulated in conformity with nature by the vital principle

(anima), and is continued to the benefit of animated beings.

The pulse, then, is produced by a double agent: first, the blood

undergoes distension or dilatation, and secondly, the vesicular membrane

of the embryo in the egg, the auricles and ventricles in the extruded

chick, effect the constriction. By these alternating motions associated,

is the blood impelled through the whole body, and the life of animals is

thereby continued.

Nor is the blood to be styled the primigenial and principal portion of

the body, because the pulse has its commencement in and through it; but

also because animal heat originates in it, and the vital spirit is

associated with it, and it constitutes the vital principle itself, (ipsa

anima); for wheresoever the immediate and principal instrument of the

vegetative faculty is first discovered, there also does it seem likely

will the living principle be found to reside, and thence take its rise;

seeing that the life is inseparable from spirit and innate heat.

For “however distinct are the artist and the instrument in things made

by art,” as Fabricius[274] well reminds us, “in the works of nature they

are still conjoined and one. Thus the stomach is the author and the

organ of chylopoesis.” In like manner are the vital principle and its

instrument immediately conjoined; and so, in whatever part of the body

heat and motion have their origin, in this also must life take its rise,

in this be last extinguished; and no one, I presume, will doubt that

there are the lares and penates of life enshrined, that there the vital

principle (anima) itself has its seat.

The life, therefore, resides in the blood, (as we are also informed in

our sacred writings,)[275] because in it life and the soul first show

themselves, and last become extinct. For I have frequently found, from

the dissection of living animals, as I have said, that the heart of an

animal that was dying, that was dead, and had ceased to breathe, still

continued to pulsate for a time, and retained its vitality. The

ventricles failing and coming to a stand, the motion still goes on in

the auricles, and finally in the right auricle alone; and even when all

motion has ceased, there the blood may still be seen affected with a

kind of undulation and obscure palpitation or tremor, the last evidence

of life. Every one, indeed, may perceive that the blood--this author of

pulsation and life,--longest retains its heat; for when this is gone,

and it is no longer blood, but gore, so is there, then, no hope of a

return to life. But, truly, as has been stated, both in the chick in ovo

and in the moribund animal, if you but apply some gentle stimulus either

to the punctum saliens or to the right auricle of the heart after the

failure of all pulsation, forthwith you will see motion, pulsation, and

life restored to the blood--provided always, be it understood, that the

innate heat and vital spirit have not been wholly lost.

From this it clearly appears that the blood is the generative part, the

fountain of life, the first to live, the last to die, and the primary

seat of the soul; the element in which, as in a fountain head, the heat

first and most abounds and flourishes; from whose influxive heat all the

other parts of the body are cherished, and obtain their life; for the

heat, the companion of the blood, flows through and cherishes and

preserves the whole body, as I formerly demonstrated in my work on the

motion of the blood.

And since blood is found in every particle of the body, so that you can

nowhere prick with a needle, nor make the slightest scratch, but blood

will instantly appear, it seems as if, without this fluid, the parts

could neither have heat nor life. So that the blood, being in ever so

trifling a degree concentrated and fixed,--Hippocrates called the state

ἀπύληψις τῶν φλεβῶν--stasis of the veins,--as in lipothymia, alarm,

exposure to severe cold, and on the accession of a febrile paroxysm, the

whole body is observed to become cold and torpid, and, overspread with

pallor and livor, to languish. But the blood, recalled by stimulants, by

exercise, by certain emotions of the mind, such as joy or anger,

suddenly all is hot, and flushed, and vigorous, and beautiful again.

Therefore it is that the red and sanguine parts, such as the flesh, are

alone spoken of as hot, and the white and bloodless parts, on the

contrary, such as the tendons and ligaments, are designated as cold. And

as red-blooded animals excel exsanguine creatures, so also, in our

estimate of the parts, are those which are more liberally furnished with

native heat and blood, held more excellent than all the others. The

liver, spleen, kidneys, lungs, and heart itself,--parts which are

especially entitled viscera,--if you will but squeeze out all the blood

they contain, become pale and fall within the category of cold parts.

The heart itself, I say, receives influxive heat and life along with the

blood that reaches it, through the coronary arteries; and only so long

as the blood has access to it. Neither can the liver perform its office

without the influence of the blood and heat it receives through the

cœliac artery; for there is no influx of heat without an afflux of blood

by the arteries, and this is the reason wherefore, when parts are first

produced, and before they have taken upon them the performance of their

respective duties, they all look bloodless and pale, in consequence of

which they were formerly regarded as spermatic by physicians and

anatomists, and in generation it was usual to say that several days were

passed in the milk. The liver, lungs, and substance of the heart itself,

when they first appear, are extremely white; and, indeed, the cone of

the heart and the walls of the ventricles are still seen to be white,

when the auricles, replete with crimson blood, are red, and the coronary

vein is purple with its stream. In like manner, the parenchyma of the

liver is white, when its veins and their branches are red with blood;

nor does it perform any duty until it is penetrated with blood.

The blood, in a word, so flows around and penetrates the whole body, and

imparts heat and life conjoined to all its parts, that the vital

principle, having its first and chief seat there, may truly be held as

resident in the blood; in this way, in common parlance, it comes to be

all in all, and all in each particular part.

But so little is it true, as Aristotle and the medical writers assert,

that the liver and the heart are the authors and compounders of the

blood, that the contrary even appears most obviously from the formation

of the chick in ovo, viz.: that the blood is much rather the fashioner

of the heart and liver; a fact, which physicians themselves appear

unintentionally to confirm, when they speak of the parenchyma of the

liver as a kind of effusion of blood, as if it were nothing more than so

much blood coagulated there. But the blood must exist before it can

either be shed or coagulated; and experience palpably demonstrates that

the thing is so, seeing that the blood is already present before there

is a vestige either of the body or of any viscus; and that in

circumstances where none of the mother’s blood can by possibility reach

the embryo, an event which is vulgarly held to occur among viviparous

animals.

The liver of fishes is always perceived of a white colour, though their

veins are of a deep purple or black; and our fowls, the fatter they

become, the smaller and paler grows the liver. Cachectic maidens, and

those who labour under chlorosis, are not only pale and blanched in

their bodies generally, but in their livers as well, a manifest

indication of a want of blood in their system. The liver, therefore,

receives both its heat and colour from the blood; the blood is in no

wise derived from the liver.

From what has now been said, then, it appears that the blood is the

first engendered part, whence the living principle in the first instance

gleams forth, and from which the first animated particle of the embryo

is formed; that it is the source and origin of all other parts, both

similar and dissimilar, which thence obtain their vital heat and become

subservient to it in its duties. But the heart is contrived for the sole

purpose of ministering between the veins and the arteries--of receiving

blood from the veins, and, by its ceaseless contractions, of propelling

it to all parts of the body through the arteries.

This fact is made particularly striking, when we find that neither is

there a heart found in every animal, neither does it necessarily and in

every instance pulsate at all times where it is encountered; the blood,

however, or a fluid which stands in lieu of it, is never wanting.

EXERCISE THE FIFTY-SECOND.

_Of the blood as prime element in the body._

It is unquestionable, then, and obvious to sense, that the blood is the

first formed, and therefore the genital part of the embryo, and that it

has all the attributes which have been ascribed to it in the preceding

exercise. It is both the author and preserver of the body; it is the

principal element moreover, and that in which the vital principle

(anima) has its dwelling-place. Because, as already said, before there

is any particle of the body obvious to sight, the blood is already

extant, has already increased in quantity, “and palpitates within the

veins,” as Aristotle expresses it,[276] “being moved hither and thither,

and being the only humour that is distributed to every part of the

animal body. The blood, moreover, is that alone which lives and is

possessed of heat whilst life continues.”

And further, from its various motions in acceleration or retardation,

in turbulence and strength, or debility, it is manifest that the blood

perceives things that tend to injure by irritating, or to benefit by

cherishing it. We therefore conclude that the blood lives of itself, and

supplies its own nourishment; and that it depends in nowise upon any

other part of the body, which is either prior to itself or of greater

excellence and worth. On the contrary, the whole body, as posthumous to

it, as added and appended as it were to it, depends on the blood, though

this is not the place to prove the fact; I shall only say, with

Aristotle,[277] that “The nature of the blood is the undoubted cause

wherefore many things happen among animals, both as regards their

tempers and their capacities.” To the blood, therefore, we may refer as

the cause not only of life in general,--inasmuch as there is no other

inherent or influxive heat that may be the immediate instrument of the

living principle except the blood,--but also of longer or shorter life,

of sleep and watching, of genius or aptitude, strength, &c. “For through

its tenuity and purity,” says Aristotle in the same place, “animals are

made wiser and have more noble senses; and in like manner they are more

timid and courageous, or passionate and furious, as their blood is more

dilute, or replete with dense fibres.”

Nor is the blood the author of life only, but, according to its

diversities, the cause of health and disease likewise: so that poisons,

which come from without, such as poisoned wounds, unless they infect the

blood, occasion no mischief. Life and death, therefore, flow for us from

the same spring. “If the blood becomes too diffluent,” says

Aristotle,[278] “we fall sick; for it sometimes resolves itself into

such a sanguinolent serum, that the body is covered with a bloody sweat;

and if there be too great a loss of blood, life is gone.” And, indeed,

not only do the parts of the body at all times become torpid when blood

is lost, but if the loss be excessive, the animal necessarily dies. I do

not think it requisite to quote any particular experiment in

confirmation of these views: the whole subject would require to be

treated specially.

The admirable circulation of the blood originally discovered by me, I

have lived to see admitted by almost all; nor has aught as yet been

urged against it by any one which has seemed greatly to require an

answer. Wherefore I imagine that I shall perform a task not less new and

useful than agreeable to philosophers and medical men, if I here briefly

discourse of the causes and uses of the circulation, and expose other

obscure matters respecting the blood; if I show, for instance, how much

it concerns our welfare that by a wholesome and regulated diet we keep

our blood pure and sweet. When I have accomplished this it will no

longer, I trust, seem so improbable and absurd to any one as it did to

Aristotle[279] in former times, that the blood should be viewed as the

familiar divinity, as the soul itself of the body, which was the opinion

of Critias and others, who maintained that the prime faculty of the

living principle (anima) was to feel, and that this faculty inhered in

the body in virtue of the nature of the blood. Thales, Diogenes,

Heraclitus, Alcmæon, and others, held the blood to be the soul, because,

by its nature, it had a faculty of motion.

Now that both sense and motion are in the blood is obvious from many

indications, although Aristotle[280] denies the fact. And, indeed, when

we see him, yielding to the force of truth, brought to admit that there

is a vital principle even in the hypenemic egg; and in the spermatic

fluid and blood a “certain divine something corresponding with the

element of the stars,” and that it is vicarious of the Almighty Creator;

and if the moderns be correct in their views when they say that the

seminal fluid of animals emitted in coitu is alive, wherefore should we

not, with like reason, affirm that there is a vital principle in the

blood, and that when this is first ingested and nourished and moved, the

vital spark is first struck and enkindled? Unquestionably the blood is

that in which the vegetative and sensitive operations first proclaim

themselves; that in which heat, the primary and immediate instrument of

life, is innate; that which is the common bond between soul and body,

and the vehicle by which life is conveyed into every particle of the

organized being.

Besides, if it be matter of such difficulty to understand the spermatic

fluid as we have found it, to fathom how through it the formation of the

body is made to begin and proceed with such foresight, art, and divine

intelligence, wherefore should we not, with equal propriety, admit an

exalted nature in the blood, and think at least as highly of it as we

have been led to do of the semen?--the rather, as this fluid is itself

produced from the blood, as appears from the history of the egg; and the

whole organized body not only derives its origin, as from a genital

part, but even appears to owe its preservation to the blood.

We have, indeed, already said so much incidentally above, intending to

speak on the subject more particularly at another time. Nor do I think

that we are here to dispute whether it is strictly correct to speak of

the blood as a _part_; some deny the propriety of such language, moved

especially by the consideration that it is not sensible, and that it

flows into all parts of the body to supply them with nourishment. For

myself, however, I have discovered not a few things connected with the

manner of generation which differ essentially from those motions which

philosophers and medical writers generally either admit or reject. At

this time I say no more on this point; but though I admit the blood to

be without sensation, it does not follow that it should not form a

portion, and even a very principal portion, of a body which is endowed

with sensibility. For neither does the brain nor the spinal marrow, nor

the crystalline or the vitreous humour of the eye, feel anything,

though, by the common consent of all, philosophers and physicians alike,

these are parts of the body. Aristotle placed the blood among the partes

similares; Hippocrates, as the animal body according to him is made up

of containing, contained, and impelling parts, of course reckoned the

blood among the number of parts contained.

But we shall have more to say on this topic when we treat of that

wherein a part consists, and how many kinds of parts there are.

Meantime, I cannot be silent on the remarkable fact, that the heart

itself, this most distinguished member in the body, appears to be

insensible.

A young nobleman, eldest son of the Viscount Montgomery, when a child,

had a severe fall, attended with fracture of the ribs of the left side.

The consequence of this was a suppurating abscess, which went on

discharging abundantly for a long time, from an immense gap in his side;

this I had from himself and other credible persons who were witnesses.

Between the 18th and 19th years of his age, this young nobleman, having

travelled through France and Italy, came to London, having at this time

a very large open cavity in his side, through which the lungs, as it was

believed, could both be seen and touched. When this circumstance was

told as something miraculous to his Serene Majesty King Charles, he

straightway sent me to wait on the young man, that I might ascertain the

true state of the case. And what did I find? A young man, well grown, of

good complexion, and apparently possessed of an excellent constitution,

so that I thought the whole story must be a fable. Having saluted him

according to custom, however, and informed him of the king’s expressed

desire that I should wait upon him, he immediately showed me everything,

and laid open his left side for my inspection, by removing a plate which

he wore there by way of defence against accidental blows and other

external injuries. I found a large open space in the chest, into which I

could readily introduce three of my fingers and my thumb; which done, I

straightway perceived a certain protuberant fleshy part, affected with

an alternating extrusive and intrusive movement; this part I touched

gently. Amazed with the novelty of such a state, I examined everything

again and again, and when I had satisfied myself, I saw that it was a

case of old and extensive ulcer, beyond the reach of art, but brought by

a miracle to a kind of cure, the interior being invested with a

membrane, and the edges protected with a tough skin. But the fleshy

part, (which I at first sight took for a mass of granulations, and

others had always regarded as a portion of the lung,) from its pulsating

motions and the rhythm they observed with the pulse,--when the fingers

of one of my hands were applied to it, those of the other to the artery

at the wrist--as well as from their discordance with the respiratory

movements, I saw was no portion of the lung that I was handling, but the

apex of the heart! covered over with a layer of fungous flesh by way of

external defence, as commonly happens in old foul ulcers. The servant of

this young man was in the habit daily of cleansing the cavity from its

accumulated sordes by means of injections of tepid water; after which

the plate was applied, and, with this in its place, the young man felt

adequate to any exercise or expedition, and, in short, he led a pleasant

life in perfect safety.

Instead of a verbal answer, therefore, I carried the young man himself

to the king, that his majesty might with his own eyes behold this

wonderful case: that, in a man alive and well, he might, without

detriment to the individual, observe the movement of the heart, and,

with his proper hand even touch the ventricles as they contracted. And

his most excellent majesty, as well as myself, acknowledged that the

heart was without the sense of touch; for the youth never knew when we

touched his heart, except by the sight or the sensation he had through

the external integument.

We also particularly observed the movements of the heart, viz.: that in

the diastole it was retracted and withdrawn; whilst in the systole it

emerged and protruded; and the systole of the heart took place at the

moment the diastole or pulse in the wrist was perceived; to conclude,

the heart struck the walls of the chest, and became prominent at the

time it bounded upwards and underwent contraction on itself.

Neither is this the place for taking up that other controversy; to wit,

whether the blood alone serves for the nutrition of the body? Aristotle

in several places contends that the blood is the ultimate aliment of the

body, and in this view he is supported by the whole body of physicians.

But many things of difficult interpretation, and that hang but

indifferently together, follow from this opinion of theirs. For when the

medical writers speak of the blood in their physiological disquisitions,

and teach that the above is its sole use and end, viz.: to supply

nourishment to the body, they proceed to compose it of four humours, or

juices, adducing arguments for such a view from the combinations of the

four primary qualities; and then they assert that the mass of the blood

is made up of the two kinds of bile, the yellow and the black, of

pituita, and the blood properly so called. And thus they arrive at their

four humours, of which the pituita is held to be cold and moist; the

black bile cold and dry; the yellow bile hot and dry; and the blood hot

and moist. Further, of each of these several kinds, they maintain that

some are nutritious, and compose the whole of the body; others, again,

they say are excrementitious. Still further, they suppose that the blood

proper is composed of the nutritious or heterogeneous portions; but the

constitution of the mass is such, that the pituita is a cruder matter,

which the more powerful native heat can convert into perfect blood.

They deny, however, that the bile can by any means be thus transformed

into blood; although the blood, they say, is readily changed into bile,

an event which they conceive takes place in melancholic diseases,

through an excess of the concocting heat.

Now, if all this were true, and there be no retrogressive movement, viz.

from black bile to bile, from bile to blood, they would be brought to

the dilemma of having to admit that all the juices were present for the

production of black bile, and that this was a principal and most highly

concocted nutriment. It would further be imperative on them to recognize

a kind of twofold blood, viz. one consisting of the entire mass of fluid

contained in the veins, and composed of the four humours aforesaid; and

another consisting of the purer, more fluid and spirituous portion, the

fluid, which in the stricter sense they call blood, which some of them

contend is contained in the arteries apart from the rest, and which they

then depute upon sundry special offices. On their own showing,

therefore, the pure blood is no aliment for the body, but a certain

mixed fluid, or rather black bile, to which the rest of the humours

tend.

Aristotle,[281] too, although he thought that the blood existed as a

means of nourishing the body, still believed that it was composed as it

were of several portions, viz. of a thicker and black portion which

subsides to the bottom of the basin when the blood coagulates, and this

portion he held to be of an inferior nature;[282] “for the blood,” he

says, “if it be entire, is of a red colour and sweet taste; but if

vitiated either by nature or disease, it is blacker.” He also will have

it fibrous in part or partly composed of fibres, which being removed, he

continues,[283] the blood neither sets nor becomes any thicker. He

farther admitted a sanies in the blood: “Sanies is unconcocted blood, or

blood not yet completely concocted, or which is as yet dilute like

serum.” And this part, he says, is of a colder nature. The fibrous he

believed to be the earthy portion of the blood.

According to the view of the Stagirite, therefore, the blood of

different animals differs in several ways; in one it is more serous and

thinner, a kind of ichor or sanies, as in insects, and the colder and

less perfect animals; in another it is thicker, more fibrous, and

earthy, as in the wild boar, bull, ass, &c. In some where the

constitution is distempered, the blood is of a blacker hue; in others it

is bright, pure, and florid, as in birds, and the human subject

especially.

Whence, it appears, that in the opinion of the physicians, as well as of

Aristotle, the blood consists of several parts, in some sort of the same

description, according to the views of each. Medical men, indeed, only

pay attention to human blood, taken in phlebotomy and contained in cups

and coagulated. But Aristotle took a view of the blood of animals

generally, or of the fluid which is analogous to it. And I, omitting all

points of controversy, and passing by any discussion of the

inconveniences that wait upon the opinions of writers in general, shall

here touch lightly upon the points that all are agreed in, that can be

apprehended by the senses, and that pertain more especially to our

subject; intending, however, to treat of everything at length elsewhere.

Although the blood be, as I have said, a portion of the body,--the

primogenial and principal part, indeed,--still, if it be considered in

its mass, and as it presents itself in the veins, there is nothing to

hinder us from believing that it contains and concocts nourishment

within itself, which it applies to all the other parts of the body. With

the matter so considered, we can understand how it should both nourish

and be nourished, and how it should be both the matter and the efficient

cause of the body, and have the natural constitution which Aristotle

held necessary in a primogenial part, viz. that it should be partly of

similar, partly of dissimilar constitution; for he says, “As it was

requisite for the sake of sensation that there should be similar members

in animal bodies, and as the faculty of perceiving, the faculty of

moving, and the faculty of nourishing, are all contained in the same

member (viz. the primogenate particle), it follows necessarily that this

member, which originally contains inherent principles of the above kind,

be extant both simply, that it may be capable of sensation of every

description, and dissimilarly, that it may move and act. Wherefore, in

the tribes that have blood, the heart is held to be such a member; in

the bloodless tribes, however, it is proportional to their state.”

Now, if Aristotle understands by the heart that which first appears in

the embryo of the chick in ovo, the blood, to wit, with its containing

parts--the pulsating vesicles and veins, as one and the same organ, I

conceive that he has expressed himself most accurately; for the blood,

as it is seen in the egg and the vesicles, is partly similar and partly

dissimilar. But if he understands the matter otherwise, what is seen in

the egg sufficiently refutes him, inasmuch as the substance of the

heart, considered independently of the blood--the ventricular cone--is

engendered long afterwards, and continues white without any infusion of

blood, until the heart has been fashioned into that form of organ by

which the blood is distributed through the whole body. Nor indeed does

the heart even then present itself with the structure of a similar and

simple part, such as might become a primogenial part, but is seen to be

fibrous, fleshy, or muscular, and indeed is obviously what Hippocrates

styled it,--a muscle or instrument of motion. But the blood, as it is

first perceived, and as it pulsates, included within its vesicle, has as

manifestly the constitution which Aristotle held necessary in a

principal part. For the blood, whilst it is naturally in the body, has

everywhere apparently the same constitution; when extravasated, however,

and deprived of its native heat, immediately, like any dissimilar

compound, it separates into several parts.

Were the blood destined by nature, however, for the nourishment of the

body only, it would have a more _similar_ constitution, like the chyle

or the albumen of the egg; or at all events it would be truly one and a

single body composed of the parts or juices indicated, like the other

humours, such as bile of either kind, and pituita or phlegm, which

retain the same form and character without the body, which they showed

within their appropriate receptacles;--they undergo no such sudden

change as the blood.

Wherefore, the qualities which Aristotle ascribed to a principal part

are found associated in the blood; which as a natural body, existing

heterogeneously or _dissimilarly_, is composed of these juices or parts;

but as it lives and is a very principal animal part, consisting of these

juices mingled together, it is an animated _similar_ part, composed of

a body and a vital principle. When this living principle of the blood

escapes, however, in consequence of the extinction of the native heat,

the primary substance is forthwith corrupted and resolved into the parts

of which it was formerly composed; first into cruor, afterwards with red

and white parts, those of the red parts that are uppermost being more

florid, those that are lowest being black. Of these parts, moreover,

some are fibrous and tough, (and these are the uniting medium of the

rest,) others ichorous and serous, in which the mass of coagulum is wont

to swim. Into such a serum does the blood almost wholly resolve itself

at last. But these parts have no existence severally in living blood; it

is in that only which has become corrupted and is resolved by death that

they are encountered.

Besides the constituents of the blood now indicated, there is yet

another which is seen in the blood of the hotter and stronger animals,

such as horses, oxen, and men also of ardent constitution. This is seen

in blood drawn from the body as it coagulates, in the upper part of the

red mass, and bears a perfect resemblance to hartshorn-jelly, or

mucilage, or thick white of egg. The vulgar believe this matter to be

the pituita; Aristotle designated it the crude and unconcocted portion

of the blood.

I have observed that this part of the blood differs both from the others

and from the mere serous portion in which the coagulated clot is wont to

swim in the basin, and also from the urine which percolates through the

kidneys from the blood. Neither is it to be regarded as any more crude

or colder portion of the blood, but rather, as I conceive, as a more

spiritual part; a conclusion to which I am moved by two motives: first,

because it swims above the bright and florid portion--commonly thought

to be the arterial blood--as if it were hotter and more highly charged

with spirits, and takes possession of the highest place in the

disintegration of the blood.

Secondly, in venesection, blood of this kind, which is mostly met with

among men of warm temperament, strong and muscular, escapes in a longer

stream and with greater force, as if pushed from a syringe, in the same

way as we say that the spermatic fluid which is ejected vigorously and

to a distance is both more fruitful and full of spirits.

That this mucaginous matter differs greatly from the ichorous or watery

part of the blood, which, as if colder than the rest, subsides to the

bottom of the basin, appears on two distinct grounds: for the watery and

sanious portion is too crude and unconcocted ever to pass into purer and

more perfect blood; and the thicker and more fibrous mucus swimming

above the clot of the blood itself appears more concoct and better

elaborated than this; and so in the resolution or separation of the

blood it comes that the mucus occupies the upper place, the sanies the

lower; the clot and red parts, however,--both those of a brighter and

those of a darker colour,--occupy the middle space.

For it is certain that not only this part, but the whole blood, and

indeed the flesh itself--as may be seen in criminals hung in chains--may

be reduced to an ichorous sanies; that is to say, become resolved into

the matters of which they were composed, like salt into the lixivium

from which it had been obtained. In like manner, the blood taken away in

any cachexy abounds in serum, and this to such an extent that

occasionally scarce any clot is seen--the whole mass of blood forms one

sanies. This is observed in leucophlegmatia, and is natural in bloodless

animals.

Further, if you take away some blood shortly after a meal, before the

second digestion has been completed and the serum has had time to

descend by the kidneys, or at the commencement of an attack of

intermittent fever, you will find it sanious, inconcoct, and abounding

in serum. On the contrary, if you open a vein after fasting, or a

copious discharge of urine or sweat, you will find the blood thick, as

if without serum, and almost wholly condensed into clot.

And in the same way as in coagulating blood you find a little of the

afore-mentioned supernatant mucus, so if you expose the sanies in

question, separated from the clot, to a gentle heat over the fire, you

will find it to be speedily changed into the mucus; an obvious

indication that the water or sanies which separates from the blood in

the basin, is perchance a certain element in the urine, but not the

urine itself, although in colour and consistence it seems so in fact.

The urine is not coagulated or condensed into a fibrous mucus, but

rather into a lixivium; the watery or sanious portion of the urine,

however, when lightly boiled, does occasionally run into a mucus that

swims through the fluid; in the same way, as the mucus in question

rendered recrudescent by corruption, liquefies and returns to the state

of sanies.

So far at this time have I thought fit to produce these my own

observations on this constituent of the blood, intending to speak more

fully of it as well as of the other constituents cognizable by the

senses, and admitted by Aristotle and the medical writers.

That I may not seem to wander too widely from my purpose, I would here

have it understood that with Aristotle I receive the blood as a part of

the living animal body, and not as it is commonly regarded in the light

of mere gore. The Stagirite says:[284] “The blood is warm, in the sense

in which we should understand warm water, did we designate that fluid by

a simple name, not viewing it as heated. For heat belongs to its nature;

just as whiteness is in the nature of a white man. But when the blood

becomes hot through any affection or passion, it is not then hot of

itself. The same thing must be said in regard to the qualities of

dryness and moistness. Wherefore, in the nature of such things they are

partly hot and partly moist; but separated, they congeal and become

cold; and such is the blood.”

The blood consequently, as it is a living element of the body, is of a

doubtful nature, and falls to be considered under two points of view.

Materially and _per se_ it is called nourishment; but formally and in so

far as it is endowed with heat and spirits, the immediate instruments of

the vital principle, and even with vitality (anima), it is to be

regarded as the familiar divinity and preserver of the body, as the

generative first engendered and very principal part. And as the prolific

egg contains within it the matter, instrument, and framer of the future

pullet, and all physicians admit a mixture of the seminal fluids of the

two sexes in the uterus during or immediately after intercourse as

constituting the mixed cause, both material and efficient, of the fœtus;

so might one with more propriety maintain that the blood was both the

matter and preserver of the body, though not the sole aliment; because

it is observed that in animals which die of hunger, and in men who

perish of marasmus, a considerable quantity of blood is still found

after death in the veins. And farther, in youthful subjects still

growing, and in aged individuals declining and falling away, the

relative quantity of blood continues the same, and is in the ratio of

the flesh that is present, as if the blood were a part of the body, but

not destined solely for its nourishment; for if it were so, no one would

die of hunger so long as he had any blood left in his veins, just as the

lamp is not extinguished whilst there is a drop of inflammable oil left

in the cruise.

Now when I maintain that the living principle resides primarily and

principally in the blood, I would not have it inferred from thence that

I hold all bloodletting in discredit, as dangerous and injurious; or

that I believe with the vulgar that in the same measure as blood is

lost, is life abridged, because the sacred writings tell us that the

life is in the blood; for daily experience satisfies us that

bloodletting has a most salutary effect in many diseases, and is indeed

the foremost among all the general remedial means: vitiated states and

plethora of the blood, are causes of a whole host of diseases; and the

timely evacuation of a certain quantity of the fluid frequently delivers

patients from very dangerous diseases, and even from imminent death. In

the same measure as blood is detracted, therefore, under certain

circumstances, it may be said that life and health are added.

This indeed nature teaches, and physicians at all events propose to

themselves to imitate nature; for copious critical discharges of blood

from the nostrils, from hemorrhoids, and in the shape of the menstrual

flux, often deliver us from very serious diseases. Young persons,

therefore, who live fully and lead indolent lives, unless between their

eighteenth and twentieth year they have a spontaneous hemorrhage from

the nose or lower parts of the body, or have a vein opened, by which

they are relieved of the load of blood that oppresses them, are apt to

be seized with fever or smallpox, or they suffer from headache and other

morbid symptoms of various degrees of severity and danger. Veterinary

surgeons are in the habit of beginning the treatment of almost all the

diseases of cattle with bloodletting.

EXERCISE THE FIFTY-THIRD.

_Of the inferences deducible from the course of the umbilical vessels in

the egg._

We find the blood formed in the egg and embryo before any other part;

and almost at the same moment appear its receptacles, the veins and the

vesicula pulsans. Wherefore, if we regard the punctum saliens as the

heart, and this along with the blood and the veins as constituting one

and the same organ, conspicuous in the very commencement of the embryo,

although we should admit that the proper substance of the heart was

deposited subsequently, still we should be ready to admit with Aristotle

that the heart (an organ made up of ventricles, auricles, vessels, and

blood) was in truth the principal and primogenate part of the body, its

own prime and essential element having been the blood, both in the order

of nature and of genetic production.

The parts that in generation succeed the blood are the veins, for the

blood is necessarily inclosed and contained in vessels; so that, as

Aristotle observes, we find two meatus venales even from the very first,

which canals, as we have shown in our history, afterwards constitute the

umbilical vessels. It seems necessary, therefore, to say something here

of the situation and course of these vessels.

In the first place, then, it is to be observed that all the arteries and

veins have their origin from the heart, and are as it were appendices or

parts added to the central organ. If therefore you carefully examine the

embryo of the human subject, or one of the lower animals, and having

divided the vena cava between the right auricle and the diaphragm, look

into it upwards or towards the heart, you will perceive three foramina,

the largest and most posterior of which tending to the spine is the vena

cava; the anterior and lesser proceeds to the root and trunk of the

umbilical vessels; the third and least of all enters the liver and is

the origin and trunk of all the ramifications distributed to the

convexity of that organ. Whence it clearly appears that the veins do by

no means all proceed from the liver as their origin and commencement,

but from the heart--unless indeed any one would be hardy enough to

contend that a vessel proceeded from its branches, not the branches from

the trunk of the vessel.

Moreover, as the vessels in question are distributed equally to the

albumen and vitellus of the egg, not otherwise than as the roots of

trees are connected with the ground, it is obvious that both of these

substances must serve for the nutriment of the embryo, and that they are

taken up and carried to it by these vessels. But this view is opposed to

that of Aristotle, who everywhere maintains that the chick is formed

from the albumen, and receives nourishment through the umbilicus alone.

The albumen indeed is first consumed, and the yelk serves subsequently

for food, supplying the place of the milk, which viviparous animals

receive after their birth from their mothers. The food which nature

provides for the young of viviparous tribes in the dug of the mother,

she supplies in the yelk of the egg to the young of oviparous animals.

Whence it happens, that when the albumen is almost wholly consumed, the

vitellus still remains nearly entire in the egg, the chick being already

perfect and complete; more than this, the yelk is still found in the

abdomen of the chick long after its exclusion. Aristotle discovered some

on the eighteenth day after the hatching; and I have myself seen a small

quantity connected with the intestine at the end of six weeks from that

epoch.

Nevertheless, from the yelk (which certainly does not decrease in the

same ratio as the albumen whilst the chick is forming) that is taken

into the abdomen of the chick, and from the distribution of vessels

through its substance, the whole of these collecting into a single trunk

which enters the porta of the liver, and doubtless earning that portion

of yelk they have absorbed for more perfect elaboration in that

viscus--these and other arguments of the like kind force me to say that

I cannot do otherwise than admit with Aristotle that the yelk supplies

food to the chick, and is analogous to milk.

The whole of the yelk, indeed, does not remain after the fœtus of the

fowl is fully formed; for a certain portion of it has been liquefied on

the very first appearance of the embryo, and receives branches of

vessels no less than the albumen, by which, already prepared, it is

carried as nourishment for the chick; still it is certain that the

greater portion of the yelk remains after the disappearance of the

albumen; that it is laid up in the abdomen of the chick when excluded,

and, attracted or absorbed by the branches of the vena portæ, that it is

finally carried to the liver.

It is manifest, therefore, that the chick when hatched, is nourished by

the yelk in the first period of its independent existence. And as within

the egg the embryo was nourished partly by the albumen, partly by the

vitellus, but principally by the albumen, which is both present in

larger quantity, and is more speedily consumed, so when the chick is

hatched, and when all the nourishment that is taken must pass through

the liver to undergo ulterior preparation, is it nourished partly by the

vitellus and partly by chyle absorbed from the intestines, but

principally by chyle, which the host of subdivisions of the mesenteric

vessels seize upon, whilst there is but a single vessel from the porta

distributed to the vitellus, and by and by but little of it remains.

Nature, therefore, acts as does the nurse, who gradually habituates her

infant to the food which is to take the place of her failing supply of

milk. The pullet is thus gradually brought from food of more easy to

food of more difficult digestion,--from yelk to chyle.

Wherefore there is every reason for what we perceive in connexion with

the course of the veins in the egg. When the embryo first begins to be

formed, they are distributed to the colliquament only, where the blood

finds suitable nutriment and matter for the formation of the body; but

by and by they extend into the thinner albumen, whence the chick, whilst

it is yet in the state of gelatine or mucor, and resembles a maggot in

form, derives its increase; the branches next extend into the thicker

albumen, and then into the vitellus, that they may also contribute to

the support of the fœtus, which, having at length arrived at maturity

and been extruded, still preserves a portion of the yelk (or milk)

within its abdomen, whereby it is maintained in part, in part by food

selected and prepared for it by the mother, until it is able to look out

for and to digest its own aliment. Thus does nature most wisely provide

food through the whole round of generation, suited to the various

strength of the digestive faculty in the future being. In the first

period of the fœtal chick’s existence a more delicate food is prepared

for it; more advanced, firmer and firmer food is supplied; and this is

the reason, I apprehend, wherefore, the perfect egg consists not only of

two portions of different colours, but is even provided with two kinds

of albumen.

Now all this that we discover from actual experience of the matter

accords with the opinion of Aristotle, where he says:[285] “The part

which is hot is best adapted to give form to the limbs; that which is

more earthy rather conduces to the constitution of the body and is more

remote. Wherefore in eggs of two colours, the animal begins to be

engendered from the white (for the beginning of animal life is in the

hot), and derives its nourishment from the yellow. In the warmer

animals, consequently, these parts are kept distinct from one another,

viz. that from which the beginning is derived, and that whence the

nourishment is obtained, and the one is white, the other yellow.”

From what has now been said it appears that the chick--and we shall show

that it is not otherwise in all other animals--arises and is constituted

as it were by a principle or soul inherent in the egg, and that in the

same way the proper aliment is sought for and is supplied within the

egg; whereby it comes that the chick is not dependent on its mother in

the same way as plants are dependent on the ground; and it is not more

correct to say that the chick is nourished by the blood of its mother,

or that its heart beats, and that it lives through the spirits of its

parent, than it would be to assert that it moved and felt through the

organs, or grew and attained to adult age through the vital principle of

its parent. It is manifest, on the contrary, and is allowed by all that

the fœtal chick is nourished through its umbilical vessels; and that the

vascular ramifications dispersed over the albumen and yelk imbibe

nourishment from them and convey it to the fœtus. It is also admitted

that the chick, when excluded from the shell, is supplied with

nourishment, partly from yelk, partly from chyle, and that in either

case the aliment passes by the same route, viz. by the vena portæ into

the liver, the branches of this vessel effecting the transit.

It is therefore obvious, as I now say by the way, that the chyle by

which all animals are nourished is brought by the mesenteric veins from

the intestines; nor is there occasion to look for any new passage--by

the lacteal vessels, to wit--or any route in adult animals other than

that which we discover in the egg and chick. But we shall recur more

fully in another place to the inconveniences of such an opinion as that

referred to.

Lastly, from the structure of the umbilical vessels of the chick in ovo,

some of which as stated in the history are veins, others arteries, it is

legitimate to conclude that there is here a circular motion of the

blood, such as we have already demonstrated in the animal body, in our

book on the Motion of the Blood, and this for the sake of the nutrition

and growth of the embryo, and because the umbilical veins are

distributed to either fluid of the egg, that they may thence bring

nutriment to the chick, and the arteries accompany the veins, that by

their affluxive heat the alimentary matter may be duly concocted,

liquefied, and made fit to answer the ends of nutrition.

And hence it happens that wherever veins--and here I would have it

understood that both arteries and veins are intended--make their way

into the albumen or vitellus, there these fluids look liquefied and

different from the rest. For as soon as the branches of the veins shoot

forth, the upper portion of the albumen in which they are implanted

passing into colliquament, becomes transparent, whilst the lower

portion, continuing thick and compact, is pushed into the inferior angle

of the egg. In like manner a separation of the vitellus, as it seems

into two portions, makes its appearance, the one being superior, and the

other inferior, and these do not differ less from one another in

character than melted differs from solid wax; now this division

corresponds to the two parts which severally receive or do not receive

blood-vessels.

Hence are we farther made more certain as to the commencement of animal

generation and the prime inherent principle of the egg. For it is

assuredly known that the cicatricula or spot on the yelk is the chief

point in the egg, that to which all the rest are subordinate, and to

which, if to any one thing more than another, is to be referred the

cause, whatever it be, of fecundity in the egg:--certain it is that the

generation of the embryo is begun within its precincts. Wherefore, as we

have said, the first effect of incubation is to cause dilatation of the

cicatricula, and the formation of the colliquament, in which the blood

first flushes and veins are distributed, and where the effects of the

native heat and the influence of the plastic power first show

themselves. And then, the more widely the ramifications of these veins

extend, in the same proportion do indications of the presence of the

vital power and vegetative force appear. For every effect is a clear

evidence of its efficient cause.

In a word I say,--from the cicatricula (in which the first trace of the

native heat appears) proceeds the entire process of generation; from the

heart the whole chick, and from the umbilical vessels the whole of the

membranes called secundines that surround it. We therefore conclude that

the parts of the embryo are severally subordinate, and that life is

first derived from the heart.

EXERCISE THE FIFTY-FOURTH.

_Of the order of the parts in Generation from an egg, according to

Fabricius._

Having already determined what part is to be esteemed the first, the

blood, to wit, with its receptacles, the heart, veins, and arteries, the

next thing we have to do is to speak of the rest of the parts of the

body and of the order and manner of their generation.