Fabricius, in whose footsteps we have resolved to tread, in speaking of

the generation of the chick in ovo, passes in review the actions which

take place in the egg, and by the effect of which the parts are

produced, discussing them _seriatim_, as if a clearer view were thence

to be obtained of the order or sequence of generation. “There are three

primary actions,” he says,[286] “which present themselves in the egg of

the bird: 1st, the generation of the embryo; 2d, its growth; 3d, its

nourishment. The first, or generation, is the proper action of the egg;

the second and third, viz. growth and nutrition, go on for the major

part without the egg, though they are begun and also perfectly performed

within it. Now these actions, as they flow from three faculties, the

generative, the nutritive, and auctive, so do three operations follow

them. From generation all the parts of the chick result; from increase

and nutrition, the growth and maintenance of its body. From studying the

formation of the chick, we perceive that, under the influence of the

generative faculty, the parts of the creature which formerly had no

existence are produced: the matter of the egg is changed into the

organized body of a chicken. But whilst any part or substance undergoes

transmutation into another, it must needs be that its proper essence

undergoes change, otherwise would it still remain as it was and

unaltered; it must at the same time receive figure, position, and

dimensions apt and convenient to its new nature; and indeed it is into

these two states or circumstances that procreation of matter resolves

itself, viz. transformation and conformation. The transformative and the

formative faculties would therefore be the cause of these functions; and

whilst one of them has produced every individual part of the chick, such

as we see it, from the chalaza of the egg, the other has given it

figure, articulations, and position, fitting it for its destined uses.

The first, the transformative or alterative faculty, is entirely

natural, and acts without all consciousness; and taking the hot, the

cold, the moist, and the dry, it alters all through the substance of the

chalaza, and in altering this substance changes it into the component

parts of the chick, that is to say, into flesh, bones, cartilages,

ligaments, veins, arteries, nerves, and all the other similar and simple

parts of the animal, and these, through the proper and innate heat and

spirit of the semen of the cock, out of the substance of the egg, that

is to say, its chalaza; by altering and commuting, it engenders,

creates, produces the proper substance of the chick, imparting at the

same time to every substance its appropriate quality. The other, which

is called the formative faculty, and which out of similar forms

dissimilar parts,--namely, giving them elegance through figure, due

dimensions, proper position, and congruous number--is much more noble

than the former, is possessed of consummate sapience, and acts not

naturally [or instinctively], but with election, and consciousness, and

intelligence. For the formative faculty appears to have exact

cognizance and foresight both of the future action and use of every part

and organ. So much of the primary action of the egg, which is the

generation of the chick, and to accomplish which both the semen of the

cock as agent and fecundator, and the chalaza as matter are required. In

the second place comes accretion or growth, which is accomplished by

nutrition, whose faculties consist in attraction, retention, concoction,

expulsion, and, finally, apposition, agglutination, and assimilation of

food.”

But for my part I neither regard such a distribution of actions as

correct, or useful, or convenient in this place. It is incorrect,

because those actions which he would make distinct in kind and in

time--for instance, that parts are first produced similar by the

alterative or transformative faculty, to be afterwards fashioned and

organized by the formative faculty, and finally made to grow by the

auctive faculty--are never apparent in the generation of the chick; for

the several parts are produced and distinguished and increased

simultaneously. For although in the generation of those animals which

are formed by metamorphosis, where from matter previously existing, and

already adequate in quantity and duly prepared, all the parts are made

distinct and conformed by transformation, as when a butterfly is formed

from a caterpillar, a silkworm from a grub, still in generation by

epigenesis the thing is very different, nor do the same processes go on

as in ordinary nutrition, which is effected by the various actions of

different parts working together to a common end, the food being here

first assumed and retained, then digested, next distributed, and finally

agglutinated. Nor is the _similar constitution_ the result of the

transformative faculty, void of all foresight, as Fabricius imagined;

but the organic comes from the formative faculty which proceeds with

both consciousness and foresight. For generation and growth do not

proceed without nutrition, nor nutrition or increase without generation;

to nourish being in other terms to substitute for a certain quantity of

matter lost as much matter of the same quality, flesh or nerve, in lieu

of the matter, flesh or nerve, that has become effete. But what is this

but to make or engender flesh or nerve? In like manner, growth cannot go

on without generation, for all natural bodies are increased by the

accession of new particles similar to those of which they formerly

consisted, and this, taking place according to all their dimensions,

they are distinguished as regards their parts, and are organized at the

same time that they grow.

But to engender the chick is in truth nothing else than to fashion or

make its several members and organs, which, although they are produced

in a certain order, and some are postgenate to others,--the less

important to the more principal organs--still, whilst the organs

themselves are all distinguished, they are not engendered in such wise

and order that the _similar_ parts are first formed, and the _organic_

parts afterwards compounded from them; or so that certain composing

parts existed before other compounded parts which must be fashioned from

them. For although the head of the chick and the rest of the body exist

in the shape of a mucus or soft jelly, whence each of the parts is

afterwards formed in sequence, and all are of _similar_ constitution in

the first instance, still are they simultaneously produced and augmented

in virtue of the same processes directed by the same agent; and in the

same proportion as the matter resembling jelly increases, in like

measure are the parts distinguished; for they are engendered,

transmuted, and formed simultaneously; similar and dissimilar parts

exist together, and from a small similar organ a larger one is produced.

The thing, in short, is not otherwise than it is among vegetables, where

from the straw proceeds the ear, the awns, and the grain--distinctly,

severally, and yet together; or as trees put forth buds, from which are

produced leaves, flowers, fruit, and finally seed.

All this we learn from an attentive study of the parts and processes of

the incubated egg, inasmuch, as from things done, actions or operations

are apprehended; from operations, faculties or forces, and from these we

then infer the artificer, generator, or cause. In the generation of the

pullet, consequently, the actions or faculties of the engendering cause

enumerated by Fabricius, namely, the metamorphic and formative, do not

differ in kind, or even in the relation of sequence, as that one is

first and the other second, but, as Aristotle is wont to say, are one

and the same in reason; not as happens with reference to the actions of

the nutritive faculty,--attraction, concoction, distribution and

apposition, to wit,--which all come into play in several places at

several times. Were this not so, the engendering cause itself would be

forced to make use of various instruments in order to accomplish its

various operations.

Fabricius, therefore, asserts erroneously that the transmutative force

works with the properties of the elements,--hot, cold, moist and dry--as

its instruments; whilst the formative faculty acts independently of

these and by a more divine power, performing its task with

consciousness, as it seems, with foresight and election. But if he had

looked more closely at the matter he would have seen that the formative

as well as the metamorphic force made use of the hot and the cold, the

moist and the dry, as instruments; nor would he have been less struck

with indications of the Supreme Artificer’s interference in the

processes of nutrition and transformation than in that of formation

itself. For nature ordained each and all of these faculties to some

definite end, and everywhere labours with forethought and intelligence.

Whatever it is in the seeds of plants which renders them fertile and

exercises a plastic force in their interior; whatever it is which in the

egg performs the duty of a most skilful artificer, producing and

fashioning the parts of the pullet, warming, cooling, moistening,

drying, concocting, condensing, hardening, softening and liquefying at

once, impressing distinctive characters on each of them by means of

configuration, situation, constitution, temperament, number and

order,--still is this something at work, disposing and ordering all with

no less of foresight, intelligence, and choice in the business of

transmuting, than in the processes of nutrition, growth, and formation.

The concoctive and metamorphic, the nutritive and augmentive faculties,

which Fabricius would have it act through the qualities of hot, cold,

moist and dry, without all consciousness, I maintain, on the contrary,

work no less to a definite end, and with not less of artifice than the

formative faculty, which Fabricius declares has knowledge and foresight

of the future action and use of every particular part and organ. In the

same way as the arts of the physician, cook and baker, in which heat and

cold, moisture and dryness, and similar natural properties are employed,

require the use of reason no less than the mechanical arts in which

either the hands or various instruments are employed, as in the business

of the blacksmith, statuary, potter, &c.; in the same way, as in the

greater world, we are told that “All things are full of Jove,”--Jovis

omnia plena--so in the slender body of the pullet, and in every one of

its actions, does the finger of God or nature no less obviously appear.

Wherefore, if from manifestations it be legitimate to judge of

faculties, we might say that the vegetative acts appear rather to be

performed with art, election, and foresight, than the acts of the

rational soul and mind; and this even in the most perfect man, whose

highest excellence in science and art, if we may take the God for our

guide, is that he KNOW HIMSELF.

A superior and more divine agent than man, therefore, appears to

engender and preserve mankind, a higher power than the male bird to

produce a young one from the egg. We acknowledge God, the supreme and

omnipotent creator, to be present in the production of all animals, and

to point, as it were, with a finger to his existence in his works, the

parents being in every case but as instruments in his hands. In the

generation of the pullet from the egg all things are indeed contrived

and ordered with singular providence, divine wisdom, and most admirable

and incomprehensible skill. And to none can these attributes be referred

save to the Almighty, first cause of all things, by whatever name this

has been designated,--the Divine Mind by Aristotle; the Soul of the

Universe by Plato; the Natura Naturans by others; Saturn and Jove by the

ancient Greeks and Romans; by ourselves, and as is seeming in these

days, the Creator and Father of all that is in heaven and earth, on whom

animals depend for their being, and at whose will and pleasure all

things are and were engendered.

Moreover, as I have said, I neither hold this arrangement of the

faculties of the vital principle, which Fabricius has placed at the head

of his account of the organs of generation, as correct in itself, nor as

useful or calculated to assist us in the matter we have in hand. For we

do not attain to a knowledge of effects from a discussion of actions or

faculties; the contrary is rather the case: from actions we ascend to a

knowledge of faculties, inasmuch as manifestations are more cognizable

to us than the powers whence they proceed, and the parts which we

investigate already formed are more readily appreciated than the actions

whence they proceed.

Neither is it well from the generation of a single chick from an egg, to

venture upon general conclusions, which can in fact only be correctly

arrived at after extensive observations on the mode of generation among

animals at large. But of this matter I shall have more to say

immediately.

Meantime, however, that we may come to the parts subservient to

generation, as Fabricius says,[287] “let us consider and perpend in what

order the organs subserving generation are produced--which are formed

first, which last. In this investigation two bases are to be laid, one

having reference to the corporeal, the other to the incorporeal; that is

to say, to nature and the vital principle. The corporeal base,” he

continues, “I call that which depends on and proceeds from the nature of

the body, and of which illustrations are readily supplied from things

made by art; as for example, that every building requires a foundation

upon which it may be established and reared; from whence walls are

raised, by which both floors and ceilings are supported; then are all

the supplementary parts added and ornaments appended:--and so, in fact,

does nature strive in the construction of the animal body; for first she

forms the bones as a foundation, in order that all the parts of the body

may grow upon and be appended to and established around them. These are

the parts, in other words, that are first formed and solidified; for as

the bones derive their origin from a very soft and membranous substance,

and by and by become extremely hard, much time is required to complete

the formation of a bone, and it is therefore that they are first

produced. Hence Galen did not compare the formation of the animal body

to every kind of artificial structure, but particularly to a ship; for

he says, as the commencement and foundation of a ship is the keel, from

which the ribs, circularly curved, proceed on either side at moderate

distances from each other, like the sticks of a hurdle, in order that

the whole fabric of the vessel may afterwards be reared upon the keel as

a suitable basis; so in the formation of the animal body does nature, by

means of the outstretched spine and the ribs drawn around it, secure a

keel and suitable foundation for the entire superstructure, which she

then raises and perfects.”

But experience teaches us that all this is very different in fact, and

that the bones are rather among the last parts to be formed. The bones

of the extremities and skull, and the teeth, do not arise any sooner

than the brain, the muscles, and the other fleshy parts: in new-born

fœtuses, perfect in other respects, the place of the bones is supplied

by mere membranes or cartilages, which are only subsequently and in the

lapse of time converted into bones; a circumstance which sufficiently

appears in the crania of new-born infants, and in the state of their

ribs and articulations.

And although it be true that the first rudiments of the body are seen in

the guise of a recurved keel, still this is a soft mucous and jelly-like

substance, which has no affinity in nature, structure, or office to

bone; and although certain globules depend from thence, the destined

rudiments of the head, still these contain no solid matter, but are mere

vesicles full of limpid water, which are afterwards formed into the

brain, cerebellum, and eyes, which are all subsequently surrounded by

the skull, at a period, however, when the beak and nails have already

acquired consistency and hardness.

This view of Fabricius is therefore both imperfect and incorrect;

inasmuch as he does not think of what nature performs in fact in the

work of generation, so much as of what in his opinion she ought to do,

betrayed into this by his comparison with the edifice reared by art. As

if nature had imitated art, and not rather art nature!--mindful of which

he himself says afterwards:[288] “It were better to say that art learned

of nature, and was an imitator of her doings; for, as Galen everywhere

reminds us, nature is both older and displays greater wisdom in her

works than art.”

And then when we admit that the bones are the foundation of the whole

body, without which it could neither support itself nor perform any

movement, it is still sufficient if they arise simultaneously with the

parts that are attached to them. And indeed the things that are to be

supported not yet existing, the supports would be established in vain.

Nature, however, does nothing in vain; nor does she form parts before

there is a use for them. But animals receive their organs as soon as the

offices of these are required. The first basis of Fabricius, therefore,

is distinctly overthrown by his own observations on the egg, and the

comparison drawn by Galen.

He appears to have come nearer the truth where he says:[289] “The other

basis of the parts to be formed first or last is obtained from nature,

that is, from the vital principle by which the animal body is ruled and

directed. If there be two grades of this principle, the vegetative and

animal, the vegetative must be held prior in point of nature and time,

inasmuch as it is common to plants and animals; and assuredly the organs

officiating in the vegetative office will be engendered and formed

before those that belong to the sensitive and motive principle,

especially to the chief organs which are in immediate relationship with

the governing principle. Now these organs are two in especial--the liver

and the heart: the liver as seat of concupiscence, of the vegetative or

nutritive faculty; the heart, as the organ whose heat maintains and

perfects the vegetative and every other faculty, and in this way has

most intimate connexions and relations with the vegetative force.

Whence, if after the third day you see the heart palpitating in the

point where the chick is engendered, as Aristotle bears witness to the

fact that you can, you will not be surprised but rather be disposed to

admit that the heart belongs to the vegetative degree and exists for its

sake. It is also consonant with reason that the liver should be

engendered simultaneously with the heart, but should lie perdue or

hidden, as it does not pulsate. And Aristotle himself admits that the

heart and liver exist in the animal body for similar reasons; so that

where there is a heart there also is a liver discovered. If the heart

and liver be the parts first produced, then, it is also fair to suppose

that the other organs subserving these two should be engendered in the

same manner,--the lungs which exist for the sake of the heart; and, for

the sake of the liver, almost all the viscera which present themselves

in the abdomen.”

Still is all this very different from the sequence we witness in the

egg. Nor is it true that the liver is engendered simultaneously with the

heart; nor does the salve avail with which he would cover that infirmity

where he says that the liver is concealed because it does not palpitate;

for the eyes and vena cava and carina are all conspicuous enough from

the commencement, although none of them palpitate. How come the liver

and lungs, if they be then extant, to be visible without any

palpitation? And then Fabricius himself has indicated a minute point

situated in the centre of his figure of the chick of the fourth day,

without stating, however, that it had any pulsation; and this he did not

perceive to be the heart, but rather believed it to be the rudiment of

the body. It is certain, therefore, that Fabricius spoke only from

conjecture and preconceived opinion of the origin of the liver; even in

the same way as others have done, Aldrovandus and Parisanus among the

number, who, lighting upon two points, and perceiving that they did not

pulsate simultaneously, straightway held that one was the heart, the

other the liver. As if the liver ever pulsated, and these two points

were aught but the two pulsating vesicles replying to each other by

alternate contractions, in the way and manner we have indicated in our

history!

Fabricius, therefore, is either deceived or deceives, when he says, “In

the first stage of the production of the chick, the liver, heart, veins,

arteries, lungs, and all the organs contained in the cavity of the

abdomen, are engendered together; and in like manner are the carina, in

other words, the head with the eyes and entire vertebral column and

thorax engendered.” For the heart, veins, and arteries are perfectly

distinguished some time before the carina; the carina, again, is seen

before the eyes; the eyes, beak, and sides before the organs contained

in the cavity of the abdomen; the stomach and intestines before the

liver or lungs; and there are still other particulars connected with the

order of production of the parts in generation, of which we shall speak

by and by.

He is also mistaken when he would have the vegetative portion of the

vital principle prior in nature and time to the sensitive and motive

element. For that which is prior in nature is mostly posterior in the

order of generation. In point of time, indeed, the vegetative principle

is prior; because without it the sensitive principle cannot exist: an

act--if the act of an organic body--cannot take place without organs;

and the sensitive and motive organs are the work of the vegetative

principle; the sensitive soul before the existence of action, is like a

triangle within a quadrangle. But nature intended that that which was

primary and most noble should also be primary; wherefore the vegetative

force is by nature posterior in point of order, as subordinate and

ministrative to the sensitive and motive faculties.

EXERCISE THE FIFTY-FIFTH.

_Of the order of the parts according to Aristotle._

The following appear to be Aristotle’s views of the order of

generation:[290] “When conception takes place, the germ comports itself

like a seed sown in the ground. For seeds likewise contain a first

principle, which, existing in the beginning in potentia, by and by when

it manifests itself, sends forth a stem and a root, by which aliment is

taken up; for increase is indispensable. And so in a conception, in

which all the parts of the body inhere in potentia, and the first

principle exists in a state of special activity.”

This principle in the egg--the body analogous to the seed of a

vegetable--we have called with Fabricius the spot or cicatricula, and

have spoken of it as a very primary part of the egg, as that in which

all the other parts inhere in potentia, and from whence each in its

order afterwards arises. In this spot, in fact, is contained

that--whatever it may be--by which the egg is made productive; and here

is the first action of the formative faculty, the first effect of the

vegetative heat revealed.

This spot, as we have said, dilates from the very commencement of the

incubation, and expands in circles, in the centre of which a minute

white speck is displayed, like the shining point in the pupil of the

eye; and here anon is discovered the punctum saliens rubrum, with the

ramifications of the sanguiferous vessels, and this as soon as the

fluid, which we have called the colliquament, has been produced.

“Wherefore,” adds Aristotle,[291] “the heart is the first part perceived

in fact; and this is in conformity not only with sense, but also with

reason. For as that which is engendered is already disjunct and severed

from both parents, and ought to rule and regulate itself like a son who

comes of age and has his separate establishment, it must therefore

possess a principle, an intrinsic principle, by which the order of the

members may be subsequently determined, and whatever is necessary to

the constitution of a perfect animal arranged. For if this principle

were at any time extrinsic, and entered into the body at a subsequent

period, you would not only be in doubt as to the time at which it

entered, but as every part is distinct, you would also see it as

necessary that that should first exist from which the other parts derive

both increase and motion.” The same writer elsewhere[292] asserts: “This

principle is a portion of the whole, and not anything added, or included

apart. For,” he proceeds, “the generation of the animal completed, does

this principle perish, or does it continue? But nothing can be shown

existing intrinsically which is not a part of the whole organized being,

whether it be plant or animal; wherefore it would be absurd to maintain

that the principle in question perished after the formation either of

any one or of any number of parts; for what should form those that were

not yet produced? Wherefore,” he continues further, “they say not well

who with Democritus assert that the external parts of animals are those

first seen, and then the internal parts, as if they were rearing an

animal of wood and stone, for such a thing would include no principle

within itself. But all animals have and hold a principle in their

interior. Wherefore the heart is seen as the first distinct part in

animals that have blood; for it is the origin of all the parts, whether

similar or dissimilar; and the creature that begins to feel the

necessity of nourishment, must already be possessed by the principle of

an animal and a full-grown fœtus.”

From the above, it clearly appears that Aristotle recognizes a certain

order and commencement in animal generation, namely, the heart, which he

regards as the first produced and first vivified part of the animal,

and, like a son set free from the tutelage of his parents, as

self-sufficing and independent, whence not only does the order of the

parts proceed, but as that by which the animal itself is maintained and

preserved, receiving from it at once life and sustenance, and everything

needful to the perfection of its being. For as Seneca says:[293] “In the

semen is comprised the entire cause of the future man; and the unborn

babe has written within it the law of a beard and a hoary head. For the

whole body and the load of future years are already traced in delicate

and obscure outlines in its constitution.”

We have already determined whether the heart were this primigenial part

or not; in other words, whether Aristotle’s words refer to that part

which, in the dissection of animals, is seen sooner than all the rest,

the punctum saliens, to wit, with its vessels full of blood; and we have

cordially assented to an answer in the affirmative. For I believe that

the blood, together with its immediate instruments, the umbilical

vessels, by which, as by roots, nutriment is attracted, and the

pulsating vesicles, by which this nutriment is distributed, to maintain

life and growth in every other part, are formed first and foremost of

all. For as Aristotle[294] has said, it is the same matter by which a

thing grows, and by which it is primarily constituted.

Many, however, err in supposing that different parts of the body require

different kinds of matter for their nourishment. As if nutrition were

nothing more than the selection and attraction of fit aliment; and in

the several parts of the body to be nourished, no concoction,

assimilation, apposition, and transmutation were required. This as we

learn, was the opinion of Anaxagoras of old:

Who held the principles of things to be

Homœomeric:--bone to be produced

Of small and slender bones; the viscera

Of small and slender viscera; the blood

Of numerous associate drops of blood.[295]

But Aristotle,[296] with the greatest propriety, observes: “Distinction

of parts is not effected, as some think, by like being carried by its

nature to like; for, besides innumerable difficulties belonging to this

opinion in itself, it happens that each similar part is severally

created; for example, the bones by themselves, the nerves, the flesh,

&c.” But the nourishment of all parts is common and homogeneous, such as

we see the albumen to be in the egg, not heterogeneous and composed of

different parts. Wherefore all we have said of the matter from which

parts are made, is to be stated of that by which they increase: all

derive nourishment from that in which they exist in potentia, though

not in act. Precisely as from the same rain plants of every kind

increase and grow; because the moisture which was a like power in

reference to all, becomes actually like to each when it is changed into

their substances severally: then does it acquire bitterness in rue,

sharpness in mustard, sweetness in liquorice, and so on.

He explains, moreover, what parts are engendered before others, and

assigns a reason which does not differ from the second basis of

Fabricius. “The cause by which, and the cause of this cause, are

different; one is first in generation, the other in essence;” by which

we are to understand that the end is prior in nature and essence to that

which happens for the sake of the end; but that which happens for the

sake of the end must be prior in generation. And on this ground

Fabricius rightly infers that all those parts which minister to the

vegetative principle, are engendered before those that serve the

sensitive principle, inasmuch as the former is subordinate to the

latter.

He subsequently adds the differences of those parts which are made for

some special purpose: some parts, for example, are instituted for a

purpose by nature, because this purpose ensues; and others because they

are instruments which the purpose employs. The former he designates

genitalia, the latter instrumenta. For the end or purpose, he says, in

some cases, is posterior, in others prior to that which is its cause.

For both the generator and the instruments it uses must exist anteriorly

to that which is engendered by or from them. The parts serving the

vegetative principle, therefore, are prior to the parts which are the

ministers of sense and motion. But the parts dedicated to motion and

sensation are posterior to the motive and sensitive faculties, because

they are the instruments which the motive and sensitive faculties

employ. For it is a law of nature that no parts or instruments be

produced before there be some use for them, and the faculty be extant

which employs them. Thus there is neither any eye nor any motive organ

engendered until the brain is produced, and the faculties preexist which

are to see and to govern motion.

In like manner, as the pulsating vesicles serve as instruments for the

motion of the blood, and the heart in its entire structure does the

same, (as I have shown in the work on the Motion of the blood,) urging

the blood in a ceaseless round through every part of the body, we see

that the blood must exist before the heart, both in the order of

generation and of nature and essence. For the blood uses the heart as an

instrument, and moreover, when engendered it continues to nourish the

organ by means of the coronary arteries, distributing heat, spirits, and

life to it through their ramifications.

We shall have further occasion to show from an entire series of

anatomical observations, how this rule of Aristotle in respect of the

true priority of the parts is borne out. Meantime we shall see how he

himself succeeds in duly inferring the causes of priority in conformity

with his rule.

“After the prime part--viz. the heart--is engendered,” he says, “the

internal parts are produced before the external ones, the superior

before the inferior; for the lower parts exist for the sake of the

superior, and that they may serve as instruments, after the manner of

the seeds of vegetables, which produce roots sooner than branches.”

Nature, however, follows no such order in generation; nor is the

instance quoted invariably applicable; for in beans, peas, and other

leguminous seeds, in acorns, also, and in grain, it is easy to see that

the stem shoots upwards and the root downwards from the same germ; and

onions and other bulbous plants send off stalks before they strike root.

He then subjoins another cause of this order, viz.: “That as nature does

nothing in vain or superfluously, it follows that she makes nothing

either sooner or later than the use she has for it requires.” That is to

say, those parts are first engendered whose use or function is first

required; and some are begun at an earlier period because a longer time

is requisite to bring them to perfection; and that so they may be in the

same state of forwardness at birth as those that are more rapidly

produced. Just as the cook, having to dress certain articles for supper,

which by reason of their hardness are done with difficulty, or require

gentle boiling for a great length of time, these he puts on the first,

and only turns subsequently to those that are prepared more quickly and

with less expenditure of heat; and further, as he makes ready the

articles that are to come on in the first course first of all, and those

that are to be presented in the second course afterwards; so also does

nature in the generation of animals only proceed at a later period to

the construction of the soft and moist and fleshy parts, as requiring

but a short time for their concoction and formation, whilst the hard

parts, such as the bones, as requiring ample evaporation and abundant

drying, and their matter long remaining inconcoct, she proceeds to

fashion almost from the very beginning. “And the same thing obtains in

the brain,” he adds, “which, large in quantity and exceedingly moist at

first, is by and by better concocted and condensed, so that the brain as

well as the eye diminishes in size. The head is therefore very large at

first, in comparison with the rest of the body, which it far surpasses

because of the brain and the eyes, and the large quantity of moisture

contained in them. These parts, nevertheless, are among the last to be

perfected, for the brain acquires consistence with difficulty, and it is

long before it is freed from cold and moisture in any animal, and

especially in man. The sinciput, too, is consolidated the last, the

bones here being quite soft when the infant sees the light.”

He gives another reason, viz. because the parts are formed of different

kinds of matter: “Every more excellent part, the sharer in the highest

principle is, farther, engendered from the most highly concocted, the

purest and first nutriment; the other needful parts, produced for the

sake of the former, from the worse and excrementitious remainder. For

nature, like the sage head of a family, is wont to throw away nothing

that may be turned to any useful purpose. But he still regulates his

household so that the best food shall be given to his children, the more

indifferent to his menials, the worst to the animals. As then, man’s

growth being complete and mind having been superadded, (in other words,

and, as I interpret the passage, adult man having acquired sense and

prudence,) things are ordered in this way, so does nature at the period

of production even compose the flesh and the other more sensitive parts

of the purest matter. Of the excrementitious remainder she makes the

bones, sinews, hair, nails, and other parts of the same constitution.

And this is the reason why this is done last of all, when nature has an

abundant supply of recrementitious material.” Our author then goes on to

speak of “a twofold order of aliment:” “one for nutrition, another for

growth;” “the nutritive is the one which supplies existence to the whole

and to the parts; the augmentative, that which causes increase to the

bulk.”

This is in accordance with what we find in the egg, where the albumen

supplies a kind of purer aliment adapted to the nutrition of the embryo

in its earlier stages, and the yelk affords the material for the growth

of the chick and pullet. The thinner albumen, moreover, as we have seen,

is used in fashioning the first and more noble parts; the thicker

albumen and the yelk, again, are employed in nourishing and making these

to grow, and further in forming the less important parts of the body.

“For,” he says, “the sinews, too, are produced in the same way as the

bones, and from the same material, viz.: the seminal and nutritive

excrementitious matter. But the nails, hair, horns, beak, and spurs of

birds, and all other things of the same description, are engendered of

the adventitious and nutritive aliment, which is obtained both from the

mother and from without.” And then he gives a reason why man, whilst

other animals are endowed by nature with defensive and offensive arms,

is born naked and defenceless, which is this: that whilst in the lower

animals these parts are formed of remainders or excrements, man is

compounded of a purer material, “which contains too small a quantity of

inconcoct and earthy matter.”

Thus far have we followed Aristotle on the subject of ‘The Order in

Generation,’ the whole of which seems to be referrible to one principle,

viz.: the perfection of nature, which in her works does nothing in vain

and has no short-comings, but still does that in the best manner which

was best to be done. Hence in generation no part would either precede or

follow, did she prefer producing them altogether, viz.: in circumstances

where she acts freely and by election; for sometimes she works under

compulsion, as it were, and beside her purpose, as when through

deficiency or superabundance of material, or through some defect in her

instruments, or is hindered of her ends by external injuries. And thus

it occasionally happens that the final parts are formed before the

instrumental parts,--understanding by final parts, those that use others

as instruments.

And as some of the parts are genital, nature making use of them in the

generation of other parts, as the means of removing obstacles the

presence of which would interfere with the due progress of the work of

reproduction, and others exist for other special ends; it therefore

happens that for the disposition of material, and other requisites, some

parts are variously engendered before others, some of them being begun

earlier but completed at a later period, some being both begun and

perfected at an earlier period, and others being begun together but

perfected at different times subsequently. And then the same order is

not observed in the generation of all animals, but this is variously

altered; and in some there is nothing like succession, but all the parts

are begun and perfected simultaneously, by metamorphosis, to wit, as has

been already stated. Hence it follows, in fine, that the primogenate

part must be of such a nature as to contain both the beginning and the

end, and be that for whose sake all the rest is made, namely, the living

principle, or soul, and that which is the potential and genital cause of

this, the heart, or in our view the blood, which we regard as the prime

seat of the soul, as the source and perennial centre of life, as the

generative heat, and indeed as the inherent heat; in a word, the heart

is the first efficient of the whole of the instrumental parts that are

produced for the ends of the soul, and used by it as instruments. The

heart, according to Aristotle, I say, is that for which all the parts of

animals are made, and it is at the same time that which is at once the

origin and fashioner of them all.

EXERCISE THE FIFTY-SIXTH.

_Of the order of the parts in generation as it appears from

observation._

That we may now propose our own views of the order of the parts in

generation as we have gathered it from our observations, it appears that

the whole business of generation in all animals may be divided into two

periods, or connected with two structures: the ovum, i. e. the

conception and seed, or that, whatever it be, which in spontaneous

productions corresponds to the seed, whether with Fernelius it be called

“the native celestial heat in the primogenial moisture,” or with

Aristotle, “the vital heat included in moisture.” For the conception in

viviparous animals, as we have said, is analogous to the seed and fruit

of plants; in the same way as it is to the egg of oviparous creatures;

to worms in spontaneously engendered animals, or to certain vesicles

fruitful by the vital warmth of their included moisture. In each and all

of these the same things inhere which might with propriety lead to their

being called seeds; they are all bodies, to wit, from which and by

which, as previously existing matter, artificer and organ, the whole of

an animal body is primarily engendered and produced.

The other structure is the embryo produced from the seed or conception.

For both the matter and the moving and efficient cause, and the

instruments needful to the operation, must necessarily precede operation

of any and every kind.

We have already examined the structure of the egg. Now the embryo to

which it gives birth, in so far as this can be made out by observation

and dissection, particularly among the more perfect animals with [red]

blood, appears to be perfected by four principal degrees or processes,

which we reduce to as many orders, in harmony with the various epochs in

generation; and we shall demonstrate that what transpires in the egg

also takes place in every conception or seed.

The first process is that of the primogenial and genital part, viz. the

blood with its receptacles, in other words, the heart and its vessels.

And this part is first engendered for two principal reasons: 1st,

because it is the principal part which uses all the rest as instruments,

and for whose sake the other parts are formed; and, 2d, because it is

the prime genital part, the origin and author of the rest. The part, in

a word, in which inhere both the principle whence motion is derived, and

the end of that motion, is obviously father and sovereign.

In the generation of this first part, which in the egg is accomplished

in the course of the fourth day, although I have not been able to

observe any order or sequence, inasmuch as the whole of its

elements,--the blood, the vessels, and the pulsating vesicles--appear

simultaneously, I have nevertheless imagined, as I have said, that the

blood exists before the pulse, because, according to nature’s laws, it

must be antecedent to its receptacles. For the substance and structure

of the heart, namely, the conical mass with its auricles and ventricles,

as they are produced long subsequently along with the other viscera, so

must they be referred to the same class of parts as these, namely, the

third.

In the production of the circulating system the veins are sooner seen

than the arteries; such at least is our conclusion.

The second process, which begins after the fourth day, is indicated by a

certain concrescence, which I designate vermiculum--worm or maggot; for

it has the life and obscure motions of a maggot; and as it concretes

into a mucous matter, it divides into two parts, the larger and superior

of which is seen to be conglobed, and divided, as it were, into thin

vesicles,--the brain, the cerebellum, and the two eyes; the less, again,

constituting the carina, arises over the vena cava and extends in the

line of its direction.

In the genesis of the head, the eyes are first perceived; by and by a

white point makes its appearance in the situation of the beak, and the

slime drying around it, it becomes invested with a membrane.

The outline of the rest of the body follows about the same period.

First, from the carina something like the sides of a ship are seen to

arise; the parts having an uniform consistence in the beginning, but the

ribs being afterwards prefigured by means of extremely fine white lines.

The instruments of locomotion next arise--the legs and wings; and the

carina and the extremities adnate to it are then distinguished into

muscles, bones, and articulations.

These two rudiments of the head and trunk appear simultaneously, but as

they grow and advance to perfection subsequently, the trunk increases

and acquires its shape much more speedily than the head; so that this,

which in the first instance exceeded the whole trunk in size, is now

relatively much smaller. And the same thing occurs in regard to the

human embryo.

The same disparity also takes place between the trunk and the

extremities. In the human embryo, from the time when it is not longer

than the nail of the little finger, till it is of the size of a frog or

mouse, the arms are so short that the extremities of the fingers could

not extend across the breast, and the legs are so short that were they

reflected on the abdomen they would not reach the umbilicus.

The proportion of the body to the extremities in children after their

birth continues excessive until they begin to stand and run. Infants,

therefore, resemble dwarfs in the beginning, and they creep about like

quadrupeds, attempting progressive motion with the assistance of all

their extremities; but they cannot stand erect until the length of the

leg and thigh together exceeds the length of the rest of the body. And

so it happens, that when they first attempt to walk, they move with the

body prone, like the quadruped, and can scarcely rise so erect as the

common dunghill fowl.

And so it happens that among adult men the long-legged--they who have

longer legs, and especially longer thighs--are better walkers, runners,

and leapers than square-built, compact men.

In this second process many actions of the formative faculty are

observed following each other in regular order, (in the same way as we

see one wheel moving another in automata, and other pieces of

mechanism,) and all arising from the same mucaginous and similar matter.

Not indeed in the manner that some natural philosophers would have it

when they say, “that like is carried to its like.” We are rather to

maintain that parts are moved, not changing their places, but remaining

and undergoing change in hardness, softness, colour, &c., whence the

diversities between _similar_ parts; those things appearing _in act_

which were before _in power_.[297] The extremities, spine, and rest of

the body, namely, are formed, grow, and acquire outline and complexion

together; the extremities, comprising bones, muscles, tendons, and

cartilages, all of which on their first appearance were similar and

homogeneous, become distinguished in their progress, and, connected

together, compose organs, by whose mutual continuity the whole body is

constituted. In like manner, the membrane growing around the head, the

brain is composed, and the lustrous eyes receive their polish out of a

perfectly limpid fluid.

That is to say, nature sustains and augments the several parts by the

same nourishment with which she fashioned them at first, and not, as

many opine, with any diversity of aliment and particles similar to each

particular structure. As she is increasing the mucaginous mass or

maggot, like a potter she first divides her material, and then indicates

the head and trunk and extremities; like a painter, she first sketches

the parts in outline, and then fills them in with colours; or like the

shipbuilder, who first lays down his keel by way of foundation, and upon

this raises the ribs and roof or deck: even as he builds his vessel does

nature fashion the trunk of the body and add the extremities. And in

this work she orders all the variety of similar parts--the bones,

cartilages, membranes, muscles, tendons, nerves, &c.--from the same

primary jelly or mucus. For thick filaments are produced in the first

instance, and these by and by are brought to resemble cords; then they

are rendered cartilaginous and spinous; and, lastly, they are hardened

and concocted into bones. In the same way the thicker membrane which

invests the brain is first cartilaginous and then bony, whilst the

thinner membrane merely consolidates into the pericranium and

integument. In similar order flesh and nerve from soft mucus are

confirmed into muscle, tendon, and ligament; the brain and cerebellum

are condensed out of a perfectly limpid water into a firm coagulum; for

the brain of infants, before the bones of the head have closed, is soft

and diffluent, and has no greater consistence than the curd of milk.

The third process is that of the viscera, the formation of which in the

chick takes place after the trunk is cast in outline, or about the sixth

or seventh day,--the liver, lungs, kidneys, cone and ventricles of the

heart, and intestines, all become visible nearly at the same moment;

they appear to arise from the veins, and to be connected with them in

the same way as fungi grow upon the bark of trees. They are, as I have

already said, gelatinous, white, and bloodless, until they take on their

proper functions. The stomach and intestines are first discovered as

white and tortuous filaments extending lengthwise through the abdomen;

along with these the mouth appears, from which a continuous canal

extends to the anus, and connects the superior with the inferior parts.

The organs of generation likewise appear about the same time.

Up to this period all the viscera, the intestines, and the heart itself

inclusive, are excluded from the cavities of the body and hang pendulous

without, attached as it were to the veins. The trunk of the body

presents itself, in fact, like a boat undecked or a house without a

roof, the anterior walls of the thorax and abdomen not being yet extant

to close these cavities.

But as soon as the sternum is fashioned the heart enters into the chest

as into a dwelling which it had built and arranged for itself; and

there, like the tutelary genius, it enters on the government of the

surrounding mansion, which it inhabits with its ministering servants the

lungs. The liver and stomach are by and by included within the

hypochondria, and the intestines are finally surrounded by the abdominal

parietes. And this is the reason wherefore without dissection the heart

can no longer be seen pulsating in the hen’s egg after the tenth day of

incubation.

About this epoch the point of the beak and the nails appear of a fine

white colour; a quantity of chylous matter presents itself in the

stomach; a little excrement is also observed in the intestine, and the

liver being now begun, some greenish bile is perceived; facts from which

it clearly appears that there is another digestion and preparation of

nutriment going on besides that which takes place by the branches of the

umbilical veins; and it is reasonable matter of doubt how the bile, the

excrementitious matter of the second digestion, can be separated by the

instrumentality of the liver from the other humours, when we see it

produced at the same time as this organ.

In the order now indicated are the internal organs generated

universally; in all the animals which I have dissected, particularly the

more perfect ones, and man himself, I have found them produced in the

same manner: in these, in the course of the second, third, and fourth

month, the heart, liver, lungs, kidneys, spleen, and intestines present

themselves inchoate and increasing, and all alike of the same white

colour which belongs to the body at large. Wherefore these early days

are not improperly spoken of as the days when the embryo is _in the

milk_; for with the exception of the veins, particularly those of the

umbilicus, everything is as it were spermatic in appearance.

I am of opinion that the umbilical arteries arise after the veins of the

same name, because the arteries are scarcely to be discovered in the

course of the first month, and take their rise from the branches that

descend to either lower extremity. I do not believe, therefore, that

they exist until that part of the body whence they proceed is formed.

The umbilical veins, on the contrary, are conspicuous long before any

part of the body is begun.

What I have now said I have derived from numerous dissections of human

embryos of almost every size; for I have had them for inspection from

the time they were like tadpoles, till they were seven or eight fingers’

breadth in length, and from thence onwards to the full time. I have

examined them more particularly, however, through the second, third, and

fourth months, in the course of which the greatest number of changes

take place, and the order of development is seen with greatest

clearness.

In the human embryo, then, of the age of two months, what we have spoken

of as taking place in the “second process,” is observed to occur. For I

rather think that during the first month there is scarcely anything of

the conception in the uterus--at all events, I have never been able to

discover anything. But the first month past, I have repeatedly seen

conceptions thrown off, and similar to the one which Hippocrates

mentions as having been voided by the female pipe-player, of the size of

a pheasant’s or pigeon’s egg. Such conceptions resemble an egg without

its shell; they are, namely, of an oval figure; the thicker membrane or

chorion with which they are surrounded, however, is seen to be covered

with a white mucor externally, particularly towards the larger end;

internally it is smooth and shining, and is filled with limpid and

sluggish water--it contains nothing else.

In the course of the second month I have frequently seen an ovum of this

description, or somewhat larger, thrown off with the symptoms of

abortion, viz. ichorous lochia; the ovum being sometimes entire, at

other times burst, and covered with bloody coagula. Within it was smooth

and slippery; it was covered with adhering blood without. Its form was

that which I have just described. In some of these aborted ova, I have

discovered embryos, in others I could find none. The embryo, when

present, was of the length of the little finger-nail, and in shape like

a little frog, save that the head was exceedingly large and the

extremities very short, like a tadpole in the month of June, when it

gets its extremities, loses its tail, and assumes the form of a frog.

The whole substance was white, and so soft and mucilaginous, that unless

immersed in clear water, it was impossible to handle it. The face was

the same as that of the embryo of one of the lower animals--the dog or

cat, for instance, without lips, the mouth gaping, and extending from

ear to ear.

Many women, whose conceptions, like the wind-eggs of fowls, are barren

and without an embryo, miscarry in the third month.

I have occasionally examined aborted ova of this age, of the size of a

goose’s egg, which contained embryos distinct in all their parts, but

misshapen. The head, eyes, and extremities were distinct, but the

muscles were indistinct; there were no bones, but certain white lines in

their situations, and as it seemed, soft cartilages. The substance of

the heart was extremely white, and consisted of two ventricles of like

size and thickness of walls, forming a cone with a double apex, which

might be compared to a small twin-kernel nut. The liver was very small

and of the general white colour. Through the whole of this time, i. e.

during the first three months, there is scarcely any appearance of a

placenta or uterine cake.

In every conception of this description I have seen, I have always found

a surrounding membrane containing a large quantity of watery fluid,

between which and the body of the embryo, suspended by its middle by

means of a long and twisted umbilical cord, there is such disproportion,

that it is impossible to regard this liquid as either sweat or urine; it

seems far more probable that like the colliquament in the hen’s egg, it

is a fluid destined by nature for the nourishment of the fœtus. Nor was

there any indication to be discovered of these conceptions or ova having

been connected with the uterus; there was only on the external surface

of their larger extremity a greater appearance of thickening and

wrinkling, as if the rudiments of the future placenta had existed there.

These conceptions, therefore, appear to me in the light of ova, which

are merely cherished within the uterus, and, like the egg in the uterus

of the fowl, grow by their own inherent powers.

In the fourth month, however, it is wonderful to find what rapid strides

the fœtus has made: from the length of the thumb it has now grown to be

a span long. All the members, too, are distinct and are tinged with

blood; the bones and muscles can be distinguished; there are vestiges of

the nails, and the fœtus now begins to move lustily. The head, however,

is excessively large; the face without lips, cheeks, and nose; the gape

of the mouth is enormous, and the tongue lies in its middle; the eyes

are small, without lids to cover them; the middle integument of the

regions of the forehead and sinciput is not yet cartilaginous, far less

bony; but the occiput is somewhat firm and in some sort cartilaginous,

indicating that the skull already begins to acquire solidity.

The organs of generation have now made their appearance, but the testes

are contained within the abdomen, in the situation of the female uterus,

the scrotum still remaining empty. The female organs are yet imperfect,

and the uterus with its tubes resembles the two-horned uterus of the

lamb.

The placenta, of larger size, and now attached to the uterus, comprises

nearly one half of the entire conception, and presented itself to my eye

as a fleshy or fungous excrescence of the womb, so firmly was its

gibbous portion connected all around with the uterine walls, which had

now grown to greater thickness. The branches of the umbilical vessels

struck into the placenta like the roots of a tree into the ground, and

by their means was the conception now, for the first time, connected

with the uterus.

The brain presented itself as a large and soft coagulum, full of ample

vessels. The ventricles of the heart were of equal capacity, and their

walls of the same thickness. In the thorax, and covered by the ribs,

three cavities, nearly of the same dimensions, were perceived; of these

the lowest was occupied by the lungs, which are full of blood, and of

the same colour as the liver and kidneys; the middle cavity was filled

by the heart and pericardium; the superior cavity, again, was possessed

by the gland called the thymus, which is now of very ample size.

In the stomach there was some chyle discovered, not very different in

character from the fluid in which the embryo swam. It also contained

some white curdled matter, not unlike the mucous sordes which the nurse

washes particularly from between the folds of the skin of new-born

infants. In the upper part of the intestines there was a small quantity

of excrementitious or chylous matter; the lower bowels contained

meconium. In the urinary bladder there was urine, and in the gall

bladder bile. The intestinum cœcum, that appendix of the colon, was

empty as in the adult, and apparently superfluous, not as in the lower

animals--the hog, horse, hare, constituting as it were another stomach.

The omentum, or apron, floated over the intestines at large like a thin

and transparent veil or cloud.

The kidneys at this epoch are not yet formed into a smooth and

continuous rounded mass, as in the adult, but are compacted of numerous

smaller masses, as we see them in the calf and sturgeon, as if there

were a renal globule or nipple placed at the extremity of each division

of the ureter, from the orifice of which the urine distilled. Over the

kidneys two bodies, first observed by Eustachius, are discovered, very

abundantly supplied with blood, so that their veins, which anatomists

designate as venæ adiposæ, are not much smaller than the emulgents

themselves. The liver and spleen, according to their several

proportions, are equally full of blood.

I may here observe, by the way, that in every strong and healthy human

fœtus we everywhere discover milk; it is particularly abundant in the

thymus gland, though it is also found in the pancreas, through the whole

of the mesentery, and in certain lacteal veins and glands, as it seems,

situated between the divisions of the mesenteric vessels. Moreover, it

can be pressed and indeed sometimes flows spontaneously from the breasts

of newly-bom infants, and nurses imagine that this is beneficial to the

infant.

And it clearly appears that this fluid, which abounds in the ovum, is no

excrementitious matter thrown off by the embryo, nothing like urine or

sweat, because its relative quantity is diminished as the period of

parturition approaches, when the fœtus is of course larger, and, as it

consumes a greater quantity of nutriment, accumulates excrementitious

matter more abundantly than it did in the first months of pregnancy. Let

it be added, that the bladder is at this time distended with urine. For

my own part I have never been able to discover that conduit for the

urine, from the bladder to the umbilicus, which anatomists describe

under the name of urachus; I have, on the contrary, frequently seen

urine escaping by the penis, but never by any urachus, when the bladder

was pressed upon with the hand.

So much for what I have observed with reference to the order of the

parts in the development of the human fœtus.

In the fourth and last process the parts of the lowest state and order

are produced, those, namely, that do not exist as needful to the being

or to the maintenance of the individual, but only as defences against

external injury, as ornaments, or as weapons of offence.

The outermost part of all, the skin, with its several

appendages,--cuticle, hair, wool, feathers, scales, shells, claws,

hooves, and other items of the same description, may be regarded as the

principal means of defence or protection. And it is well devised by

nature, who, indeed, never does aught amiss, that these parts are the

last to be engendered, inasmuch as they could never be of use or avail

as defences until the animal was born. The common domestic pullet is

therefore born covered with down only, not with feathers, like certain

other birds which have to be speedily prepared for flight, because it

has to seek its food on foot, not on the wing, and by active running

about hither and thither. In like manner the young of ducks and geese,

which feed swimming, have their feathers and wings perfected at a later

period than their feet and legs. It is otherwise with swallows, however,

which have to fly sooner than to walk, because they feed on the wing.

The down of the pullet begins to appear after the fourteenth day, the

fœtus being already perfect in all its parts. When the feathers first

show themselves, they are in the guise of points within the skin, but by

and by the feathers project, like plants from the ground, increase in

length, become unfolded, invest the whole body, and protect it against

the inclemencies of the atmosphere.

Feathers differ from quills in form, use, place of growth, and order of

production. The pullet is feathered before it has any quills, for the

quill-feathers only grow in the wings and tail, and also spring more

deeply, from the very lowest part of the integument, or even from the

periosteum, and serve essentially as instruments of motion; the feathers

again arise superficially from the skin, and are everywhere present as

means of protection.

“Nails, hair, horn, and the like,” says Aristotle,[298] “are engendered

from the skin; whence it happens that they change colour with the skin;

for the white and black and particoloured are so in consequence of the

colour of the skin whence they arise.” In the bird, however, this is

not so; for whatever the colour of the feathers, the skin is still never

otherwise than of one tint, viz., white. And then the same feather or

quill is frequently seen of different and often brilliant colours in

different parts for the ornament of the creature.

In the human fœtus the skin and all the parts connected with it are in

like manner perfected the last of all. In the earlier periods,

consequently, we find neither lips, cheeks, external ears, eyelids, nor

nose; and the last part to grow together is the upper lip in the course

of the middle line of the body.

Man comes into the world naked and unarmed, as if nature had destined

him for a social creature, and ordained him to live under equitable laws

and in peace; as if she had desired that he should be guided by reason

rather than be driven by force; therefore did she endow him with

understanding, and furnish him with hands, that he might himself

contrive what was necessary to his clothing and protection. To those

animals to which nature has given vast strength, she has also presented

weapons in harmony with their powers; to those that are not thus

vigorous, she has given ingenuity, cunning, and singular dexterity in

avoiding injury.

Ornaments of all kinds, such as tufts, crests, combs, wattles, brilliant

plumage, and the like, of which some vain creatures seem not a little

proud, to say nothing of such offensive weapons as teeth, horns, spurs,

and other implements employed in combat, are more frequently and

remarkably conferred upon the male than the female. And it is not

uninteresting to remark, that many of these ornaments or weapons are

most conspicuous in the male at that epoch when the females come into

season, and burn with desire of engendering. And whilst in the young

they are still absent, in the aged they also fail as being no longer

wanted.

Our common cock, whose pugnacious qualities are well known, so soon as

he comes to his strength and is possessed of the faculty of engendering,

is distinguished by his spurs, and ornamented with his comb and

beautiful feathers, by which he charms his mates to the rites of Venus,

and is furnished for the combat with other males, the subject of dispute

being no empty or vainglorious matter, but the perpetuation of the stock

in this line or in that; as if nature had intended that he who could

best defend himself and his, should be preferred to others for the

continuance of the kind. And indeed all animals which are better

furnished with weapons of offence, and more warlike than others, fall

out and fight, either in defence of their young, of their nests or dens,

or of their prey; but more than all for the possession of their females.

Once vanquished, they yield up possession of these, lay aside their

strut and haughty demeanour, and, crest-fallen and submissive, they seem

to consume with grief; the victor, on the contrary, who has gained

possession of the females by his prowess, exults and boastfully

proclaims the glory of his conquest.

Nor is this ornamenting anything adventitious and for a season only; it

is a lasting and special gift of nature, who has not been studious to

deck out animals, and especially birds only, but has also thrown an

infinite variety of beautiful dyes over the lowly and insensate herbs

and flowers.

EXERCISE THE FIFTY-SEVENTH.

_Of certain paradoxes and problems to be considered in connexion with

this subject._

Thus far have we spoken of the order of generation, whereby the

differences between those creatures that are engendered by metamorphosis

and those that are developed by epigenesis, as well as between those

that are said to proceed from a worm and those that arise from an egg,

have been made to appear. The latter are partly incorporated from a

prepared matter, and are nourished and increased from a certain

remaining matter; the former are incorporated from the whole of the

matter present; the latter grow and are formed simultaneously, and after

their birth continue to wax in size and finally attain maturity; the

former increase at once, and from a grub or caterpillar grow into an

aurelia, and are then produced, consummately formed, as butterflies,

moths, and the like. Wherefore Aristotle, as Fabricius[299] observes:

“As he assigns a sort of twofold nature to the egg, and a twofold egg

in this kind, so does he assert a twofold action and a twofold animal

engendered. For,” he proceeds, “from the first eggs, which are the

primordia of generation, a worm is constantly produced; viz.: from the

eggs of flies, ants, bees, silkworms, &c., in which some fluid is

contained, and from the whole of which fluid the worm is engendered; but

from the second eggs, formed by the worms themselves, butterflies are

engendered and disclosed, viz.: flying animals contained in a shell, or

follicle, or egg, which shell giving way the winged creature escapes;

precisely as Aristotle[300] has it where he speaks of the egg of the

locust.” Finally, whilst the higher animals produced from eggs are

perfected by a succession of parts, the lower creatures that arise in

this way, or that are formed by metamorphosis, are produced at one

effort, as it were, and entire. And in the same way are engendered both

those creatures that are said to arise spontaneously, by chance or

accident, and derive their first matter or take their origin from

putrefaction, filth, excrement, dew, or the parts of plants and animals,

as well as those that arise congenerately from the semen of animals.

Because this is common to all living creatures, viz.: that they derive

their origin either from semen or eggs, whether this semen have

proceeded from others of the same kind, or have come by chance or

something else. For what sometimes happens in art occasionally occurs in

nature also; those things, namely, take place by chance or accident

which otherwise are brought about by art. Of this Aristotle[301] quotes

health as an illustration. And the thing is not different as respects

the generation, in so far as it is from seed, of certain animals: their

semina are either present by accident, or they proceed from an univocal

agent of the same kind. For even in fortuitous semina there is an

inherent motive principle of generation, which procreates from itself

and of itself; and this is the same as that which is found in the semina

of congenerative animals,--a power, to wit, of forming a living

creature. But of this matter we shall have more to say shortly.

From what has just been said, however, several paradoxes present

themselves for consideration. For when we see the cicatricula enlarging

in the egg, the colliquament concocted and prepared, and a variety of

other particulars all tending, not without foresight, to the development

of the embryo, before the first rudiment or the merest particle of this

is conspicuous, what should hinder us from believing that the calidum

innatum and the vegetative soul of the chick are in existence before the

chick itself? For what is competent to produce the effects and acts of

life, except their efficient cause and principle, heat, namely, and the

faculty of the vegetative soul? Therefore it would seem that the soul

was not the act of the organic body possessing life in potentia; for we

regard the chick with its appropriate form as the consequence of such an

act. But where can we suppose the form and vital principle of the chick

to inhere save in the chick itself? unless indeed we admitted a

separation of forms and conceded a certain metamorphosis.

Now this appears most obviously where the same animal lives, as

Aristotle has it, by or under a succession of forms, for example, a

caterpillar, a chrysalis, a butterfly. For it is of necessity the same

efficient, nutrient, and conservative principle that possesses each of

these, although under different forms; unless we allow that there is one

vital principle in the youth, another in the man, a third in the aged

individual, or maintain that the forms of the grub and caterpillar are

the same as those of the silkworm and butterfly. Aristotle has entered

very fully into this subject, and we shall ourselves have more to say on

it immediately.

It appears further paradoxical to maintain that the blood is produced,

and moves to and fro, and is imbued with vital spirits, before any

sanguiferous or locomotive organs are in existence. Neither is it less

new and unheard-of to assert, that sensation and motion belong to the

fœtus before the brain is formed; for the fœtus moves, contracting and

unfolding itself, when there is nothing more than a little limpid water

in the place of the brain.

Moreover, the body is nourished and increases before the organs

appropriated to digestion, viz. the stomach and abdominal viscera, are

formed. Sanguification, too, which is entitled the second digestion, is

perfect before the first, or chylification, which takes place in the

stomach, is begun. The excrementitious products of the first and second

digestions, namely, excrement in the intestines, urine and bile in the

urinary and gall bladder, are contemporaneous with the existence of the

concocting organs themselves. Lastly, not only is there a soul or vital

principle present in the vegetative part, but even before this there is

inherent mind, foresight, and understanding, which from the very

commencement to the being and perfect formation of the chick, dispose

and order and take up all things requisite, moulding them in the new

being, with consummate art, into the form and likeness of its parents.

In reference to this subject of family likeness, we may be permitted to

inquire as to the reason why the offspring should at one time bear a

stronger resemblance to the father, at another to the mother, and, at a

third, to progenitors, both maternal and paternal, further removed?

particularly in cases where at one bout, and at the same moment, several

ova are fecundated. And this too is a remarkable fact, that virtues and

vices, marks and moles, and even particular dispositions to disease are

transmitted by parents to their offspring; and that while some inherit

in this way, all do not. Among our poultry some are courageous, and

pugnaciously inclined, and will sooner die than yield and flee from an

adversary; their descendants, once or twice removed, however, unless

they have come of equally well-bred parents, gradually lose this

quality; according to the adage, “the brave are begotten by the brave.”

In various other species of animals, and particularly in the human

family, a certain nobility of race is observed; numerous qualities, in

fact, both of mind and body, are derived by hereditary descent.

I have frequently wondered how it should happen that the offspring,

mixed in so many particulars of its structure or constitution, with the

stamp of both parents so obviously upon it, in so many parts, should

still escape all mixture in the organs of generation; that it should so

uniformly prove either male or female, so very rarely an hermaphrodite.

Lastly, many things are present before they appear, and some are begun

among the very first which are completed among the very last, such as

the eyes, the organs of generation, and the beak.

Several doubts and difficulties have thence arisen as to the

principality and relative dignity of the several members, in which they

who are fond of such things have displayed their ingenuity. Among the

number: whether the heart gives life and virtue to the blood; or,

rather, the blood to the heart. Whether the blood be extant for the sake

of the body as matter, nourishment, and instrument; or, on the contrary,

the body and its parts are the cause of the blood, and constituted for

the sake of the vital principle which especially inheres in it. In like

manner, whether the auricles or the ventricles of the heart are the

chief, the auricles being the first to live and pulsate, the last to

die. Further, whether the left ventricle, which in man is of greater

length, and is also surrounded with thicker and more fleshy walls, and

is regarded as the source of the spirits, be hotter, more spirituous,

excitable, and excellent, than the right, which contains a larger

quantity of blood, and is the last to become unstrung by death; in which

the blood of the dying accumulates, congeals, and is deprived of life

and spirit; to which, moreover, as to a fountain head, the first

umbilical veins bring their blood, and from which they themselves derive

their origin.

So much appears from careful observation of the order observed in the

production of the parts, and certain other points that follow as

deductions from these, and do not a little militate against the commonly

received physiological doctrines, viz.: since it is manifest that

sensation and motion exist before the brain, all sensation and motion do

not proceed from the brain; from our history it is clearly ascertained

that sense and movement inhere in the very first drop of blood produced

in the egg, before there is a vestige of the body. The first scaffolding

or rudiment of the body, too, which we have said is merely mucilaginous,

before any of the extremities are visible, and when the brain is nothing

more than a limpid fluid, if lightly pricked, will move obscurely, will

contract and twist itself like a worm or caterpillar, so that it is very

evidently possessed of sensation.

There are yet other arguments deduced from sense and motion whence we

should infer that the brain was not so much the first principle of the

body, in the way the medical writers maintain, as the heart, agreeably

to Aristotle’s view.

The motions and actions which physicians style _natural_, because they

take place involuntarily, and we can neither prevent nor moderate,

accelerate nor retard them by our will, and they therefore do not

depend on the brain, still do not occur entirely without causing

sensation, but proclaim themselves subject to sense, inasmuch as they

are aroused, called forth, and changed thereby. When the heart, for

example, is affected with palpitation, tremor, lipothymia, syncope, and

with great variety in the extent, rapidity, and order or rhythm of its

pulsations, we do not hesitate to ascribe these to morbific causes

implicating, deranging its sensation. For whatever by its divers

movements strives against irritations and troubles must necessarily be

endowed with sensation.

The stomach and bowels, disturbed by the presence of vitiated humours,

are affected with ructus, flatus, vomiting, and diarrhœa; and as it lies

not in our power either to provoke or to restrain their motions, neither

are we aware of any sensation dependent on the brain which should arouse

the parts in question to motions of the kind.

It is truly wonderful to observe the effect of taking a solution of

antimony, which we neither distinguish by the taste, nor find any

inconvenience from, whether in the swallowing or the rejection.

Nevertheless there is a certain discriminating sense in the stomach

which distinguishes what is hurtful from what is useful, and by which

vomiting is induced.

Nay, the flesh itself readily distinguishes a poisoned wound from one

that is not poisoned, and on receipt of the former contracts and

condenses itself, whereby phlegmonous tumours are produced, as we find

in connexion with the stings of bees, gnats, and spiders.

I have myself, for experiment’s sake, occasionally pricked my hand with

a clean needle, and then having rubbed the same needle on the teeth of a

spider, I have pricked my hand in another place. I could not by my

simple sensation perceive any difference between the two punctures;

nevertheless there was a capacity in the skin to distinguish the one

from the other; for the part pricked with the envenomed needle

immediately contracted into a tubercle, and by and by became red, and

hot, and inflamed, as if it collected and girded itself up for a contest

with the poison for its overthrow.

The sensations which accompany affections of the uterus, such as

twisting, decubitus, prolapse, ascent, suffocation, &c., and other

inconveniences and irritations, do not depend on the brain or on common

sensation; yet neither are these to be presumed as happening without all

consciousness. For that which is wholly without sense is not seen to be

irritated by any means, neither can it be stimulated to motion or action

of any kind. Nor have we any other means of distinguishing between an

animate and sentient thing and one that is dead and senseless than the

motion excited by some other irritating cause or thing, which as it

incessantly follows, so does it also argue sensation.

But we shall have an opportunity of speaking farther of this matter when

we discuss the actions and uses of the brain. Respect for our

predecessors and for antiquity at large inclines us to defend their

conclusions to the extent that love of truth will allow. Nor do I think

it becoming in us to neglect and make little of their labours and

conclusions who bore the torch that has lighted us to the shrine of

philosophy. I am, therefore, of opinion that we should conclude in this

way: we have consciousness in ourselves of five principal senses, by

which we judge of external objects; but we do not feel with the same

sense by means of which we are conscious that we feel--seeing with our

eyes, we still do not know by them that we see, but by another sense or

sensitive organ, namely, the internal common sensation or common

sensorium, by which we examine those things that reach us through each

of the external sensoria, and distinguish that which is white from that

which is sweet or hard. Now this sensorium commune to which the species

or impressions of all the external instruments of sensation are

referred, is obviously the brain, which along with its nerves and the

external organs annexed, is held and esteemed to be the adequate

instrument of sensation. And this brain is like a sensitive root to

which a variety of fibres tend, one of which sees, another hears, a

third touches, and a fourth and a fifth smell and taste.

But as there are some actions and motions the government or direction of

which is not dependent on the brain, and which are therefore called

_natural_, so also is it to be concluded that there is a certain sense

or form of touch which is not referred to the common sensorium, nor in

any way communicated to the brain, so that we do not perceive by this

sense that we feel; but, as happens to those who are deranged in mind,

or who are agitated to such a degree by violent passion that they feel

no pain, and pay no regard to the impressions made on their senses, so

must we believe it to be with this sense, which we therefore distinguish

from the proper animal sense. Now such a sense do we observe in

zoophytes or plant-animals, in sponges, the sensitive plant, &c.

Wherefore, as many animals are endowed with both sense and motion

without having a common sensorium or brain, such as earthworms,

caterpillars of various kinds, chrysalides, &c., so also do certain

natural actions take place in the embryo and even in ourselves without

the agency of the brain, and a certain sensation takes place without

consciousness. And as medical writers teach that the natural differ from

the animal actions, so by parity of reason does the natural sense of

touch differ from the animal sense of touch,--it constitutes, in a word,

another species of touch; and whilst the one is communicated to the

common sensorium, the other is not so communicated.

Further, it is one thing for a muscle to be contracted and moved, and

another for it by regulated contractions and relaxations to perform any

movement, such as progression or prehension. The muscles or organs of

motion, when affected with spasms or convulsions from an irritating

cause, are assuredly moved no otherwise than the decapitated cock or

hen, which is agitated with many convulsive movements of its legs and

wings, but all confused and without a purpose, because the controlling

power of the brain has been taken away:--common sensation has

disappeared, under the controlling influence of which these motions were

formerly coordinated to progression by walking or to flight.

We therefore conceive the fact to be that all the natural motions

proceed from the power of the heart, and depend on it; the spontaneous

motions, however, and those that complete any motion which physicians

entitle an animal motion, cannot be performed without the controlling

influence of the brain and common sensation. For inasmuch as by this

common sensation we are conscious of our perceptions, so also are we

conscious that we move, and this whether the motion be regular or

otherwise.

We have an excellent example of both of these kinds of motion in

respiration. For the lungs, like the heart, are continually carried

upwards and downwards by a natural movement, and are excited by any

irritation to coughing and more frequent action; but they cannot form

and regulate the voice, nor can singing be executed, without the

assistance, and in some sort the command, of the sensorium commune.

But these matters will be more fully handled when we come to speak of

the actions and uses of the brain, and to consider the vital principle

or soul. So much we have thought fit to say by the way, that we might

show the respect in which we hold our illustrious teachers, and our

anxiety to carry them along with us in our labours.

EXERCISE THE FIFTY-EIGHTH.

_Of the nutrition of the chick in ovo._

That the authority of the ancients is not to be rashly thrown off

appears in this: it was formerly current doctrine, though many at the

present day, Fabricius[302] among the number, reject it as a delusion

and a foolish idea, that the embryo sucked in its mother’s womb. This

idea nevertheless had Democritus, Epicurus, and Hippocrates for its

supporters; and the father of physic contends for it on two principal

grounds: “Unless the fœtus sucked,” he says,[303] “how should excrements

be formed? or how should it know how to suck immediately after it is

born?”

Now, whilst in other instances it is customary to swear by the bare

statement of this ancient and most distinguished writer, his _ipse

dixit_ (ἀυτὸς ἔφη) sufficing, because he here makes an assertion

contrary to the commonly received opinion, Fabricius not only denies the

statement, but spurns the arguments in support of his conclusion. We,

however, leave it to the judgment of skilful anatomists and learned

physicians to say whether our observations on the generation of animals

do not proclaim this opinion of Hippocrates to be not merely probable,

but even necessary.

All admit that the fœtus in utero swims in the midst of an abundance of

a watery fluid, which in our history of the egg we have spoken of as the

colliquament, this fluid modern authorities regard as the sweat and

excrement of the fœtus, and ascribe as its principal use the protection

of the uterus against injury from the fœtus during any violent motion of

the mother in running or leaping; and, on the other hand, the defence of

the fœtus from injury through contact with neighbouring bones, or an

external cause, particularly during the period when its limbs are still

delicate and weak.

Fabricius[304] ascribes additional uses to this fluid, viz. “that it may

moisten and lubricate all the parts around, and dispose the neck of the

uterus to facile and speedy dilatation to the utmost extent; and all

this is not less assisted by that thick, white, excrementitious matter

of the third digestion, neglected by the ancients, which is unctuous and

oily, and farther prevents the sweat, which may occasionally be secreted

sharp and salt in quality, from excoriating the tender body of the

fœtus.”

I readily acknowledge all the uses indicated, viz. that the tender fœtus

may be secure against all sudden and violent movements of the mother,

that he may ride safe in the “bat’s wings,” as they are called, and,

surrounded with an abundance of water, that he may escape coming into

contact with his mother’s sides, being restrained by the retinacular

fluid on either hand: this circumambient fluid must certainly protect

the body which floats in its middle from all external injury. But, as in

many other instances, my observations compel me here to be of a

different opinion from Fabricius. In the first place, I am by no means

satisfied that this fluid is the sweat of the fœtus. And then I do not

believe that the fluid serves those important purposes in parturition

which he indicates; and much less that it is ever so sharp and saline

that an unctuous covering was requisite to protect the fœtus from its

erosive effects, particularly in those cases where there is already a

thick covering of wool, or hair, or feathers. The fluid, in fact, has a

pleasant taste, like that of watery milk, so that almost all viviparous

animals lap it up, and cleanse their new-born progeny by licking them

with their tongues, greedily swallowing the fluid, though none of them

was ever seen to touch any of the excrements of their young.

Fabricius spoke of this fluid as saline and acrimonious, because he

believed it to be sweat. But what inconvenience, I beseech you, were

sweat to the chick, already covered with its feathers?--if indeed any

one ever saw a chicken sweat. Nor do I think he could have said that the

use of this fluid in the egg was, by its moistening and lubrifying

qualities, to facilitate the birth of the chick; for the drier and older

the shell of the egg, the more friable and fragile it becomes. Finally,

were it the sweat of the embryo, or fœtus, it ought to be most abundant

nearest the period of parturition: the larger the fœtus and the more

food it consumes, the more sweat must it necessarily secrete. But

shortly before the exclusion of the chick from the egg, namely, about

the nineteenth or twentieth day, there is none of the fluid to be seen,

because as the chick grows it is gradually taken up; so that if the

thing be rightly viewed, the fluid in question ought rather to be

regarded as nutriment than as excrement, particularly as he has said

that the chick in the egg breathes, and lets its chirping be heard,

which it certainly would not do were it surrounded with water.

But all experienced obstetricians know that the watery fluid of the

secundines is of no great use either in lubricating the parts or in

facilitating the progress of parturition in the way Fabricius would have

it. For the parts surrounding the vulva are relaxed of themselves, and

by a kind of proper maturity at the full time, without any assistance

from the uterine waters; and particularly those that offer the greatest

obstacles to the advance of the fœtus, namely, the ossa pubis and the os

coccygis, to which the attention of the midwife is especially directed

in assisting the woman in labour. For midwives are much less studious to

anoint the soft parts with any emollient salves, lest they tear, than

careful to pull the os coccygis outwards, a business in which, if the

fingers do not suffice, they have recourse to the uterine speculum,

applied by the hand of the experienced surgeon, an instrument having

three sides or branches, one of which bearing on the os coccygis, the

other two on the ossa pubis, the business of distension is effected by

force. For the head of the child that is about to be born, when it

makes the turn, and is forced downwards, relaxes and opens the os uteri;

but coming down he will stick fast, and scarcely be brought forth if he

chance to abut upon the point of the os coccygis, and immediately the

case is one not without danger both to the child and mother. But

nature’s intention was obviously to relax and soften all the parts

concerned; and the attendant knows that when the uterine orifice is

discovered in a soft and lax condition, by the finger introduced, it is

an infallible sign that the delivery is at hand even though the waters

have not broken. Indeed--and I do not speak without experience--if

anything remains in the uterus for expulsion, either after delivery or

at any other time, and the uterus make efforts to get rid of it, the

orifice both descends lower and is found soft and relaxed. If the

uterine orifice recedes, and is found somewhat hard after delivery, it

is a sign of the woman’s restoration to health.

Taught by like experience, I assert that the ossa pubis frequently

become loosened during labour, their cartilaginous connexion being

softened, and the whole hypogastric region enlarged in the most

miraculous manner, not, however, by any pouring out of watery fluids,

but spontaneously, as ripe fruit gapes that the included seed may find

an exit. The degree in which the coccyx may impede delivery, however, is

apparent among quadrupeds having tails, which can neither bring forth,

nor even discharge the excrement from their bowels, unless the tail be

raised; if you but depress the tail with your hand, you prevent the exit

of the dung.

Moreover, the most natural labour of all is held to be that in which the

fœtus and afterbirth, the waters inclusive, or the ovum, is expelled

entire. Now if the membranes have not given way, and the waters have not

escaped, it comes to pass that the surrounding parts are more than

usually distended and dilated by the labour pains, in consequence, to

wit, of the entire and tense state of the membranes, by which it happens

that the fœtus is produced more speedily, and with a less amount of

effort, although with more suffering to the mother. In cases of this

kind we have known women who were suffering much in their travail in

consequence of the too great distension, immensely relieved by the

rupture of the membranes and the sudden escape of the waters, the

laceration being effected either with the nails of the midwife or the

use of a pair of forceps.

Experienced midwives are farther aware that if the waters come away

before the orifice of the uterus is duly dilated, the woman is apt to

have a lingering time and a more difficult delivery, contrary to

Fabricius’s notion of the waters having such paramount influence in

softening and lubricating the parts.

Moreover, that the fluid which we have called colliquament is not the

sweat of the fœtus is made obvious, both from the history of the egg and

of the uterogestation of other animals: it is present before the fœtus

is formed in any way, before there is a trace of it to be seen; and

whilst it is still extremely small and entirely gelatinous, the quantity

of water present is very great, so that it seems plainly impossible that

so small a body should produce such a mass of excrementitious fluid.

It happens besides that the ramifications of the umbilical veins are

distributed over and terminate upon the membrane which incloses this

fluid, precisely as on the membranes of the albumen and yelk of the egg,

a circumstance from which, and the thing being viewed as it is in fact,

it appears to be clearly proclaimed that this fluid is rather to be

regarded as food than as excrement.

To me, therefore, the opinion of Hippocrates appears more probable than

that of Fabricius and other anatomists, who look on this liquid as

sweat, and believe that it must prove detrimental to the fœtus. I am

disposed, I say, to believe that the fluid with which the fœtus is

surrounded may serve it for nourishment; that the thinner and purer

portions of it, taken up by the umbilical veins, may serve for the

constitution and increase of the first formed parts of the embryo; and

that from the remainder or the milk, taken into the mouth by suction,

passed on to the stomach by the act of deglutition, and there digested

or chylified, and finally absorbed by the mesenteric veins, the new

being continues to grow and be nourished. I am the more disposed to take

this view from certain not impertinent arguments, which I shall proceed

to state.

As soon as the embryo acquires a certain degree of perfection it moves

its extremities, and begins to prove the actions of the organs destined

to locomotion. Now I have seen the chick in ovo, surrounded with liquid,

opening its mouth, and any fluid that thus gained access to the fauces

must needs have been swallowed; for it is certain that whatever passes

the root of the tongue and gains the top of the œsophagus, cannot be

rejected by any animal with a less effort than that of vomiting. This

fact is acted upon every day by veterinary practitioners, who in

administering medicated drinks and pills or boluses to cattle, seize the

tongue, and having put the article upon its root beyond the protuberant

part, the animal cannot do otherwise than swallow it. And if we make the

experiment ourselves, we find that a pill carried between the finger and

thumb as far as the root of the tongue and there dropped, immediately

the action of deglutition is excited, and unless vomiting be produced

the pill is taken down. If the embryo swimming in the fluid in question,

then, do but open his mouth, it is absolutely necessary that the fluid

must reach the fauces; and if the creature then move other muscles,

wherefore should we not believe that he also uses his throat in its

appropriate office and swallows the fluid?

It is further quite certain that in the crop of the chick,--and the same

thing occurs in reference to the stomach of other embryos--there is a

certain matter having a colour, taste, and consistence, very similar to

that of the liquid mentioned, and some of it in the stomach digested to

a certain extent, like coagulated milk; and further, whilst we discover

a kind of chyle in the upper intestines, we find the lower bowels full

of stercoraceous excrements. In like manner we perceive the large

intestines of the fœtuses of viviparous animals to contain excrements of

the same description as those that distend them when they feed on milk.

In the sheep and other bisulcated animals we even find scybala.

Towards the seventeenth day we find dung very obviously near the anus of

the chick; and shortly before the extrusion I have seen the same matter

expelled and contained within the membranes. Volcher Coiter, a careful

and experienced dissector, states that he has observed the same thing.

Wherefore should we doubt, then, that the fœtus in utero sucks, and that

chylopoiesis goes on in its stomach, when we find present both the

principles and the recrementitious products of digestion?

And then, when we find the bladder both of the bile and the urine full

of those excrements of the second digestion, wherefore should we not

conclude that the first digestion, or chylopoiesis, has preceded?

The embryo, therefore seeks for and sucks in nourishment by the mouth;

and you will readily believe that he does so if you rip him from his

mother’s womb and instantly put a finger in his mouth; which Hippocrates

thinks he would not seize had he not previously sucked whilst in the

womb. For we are accustomed to see young infants trying various motions,

making experiments, as it were, approaching everything, moving their

limbs, attempting to walk, and uttering sounds, acts all of which when

taught by repeated experience, they afterwards come to execute with

readiness and precision. But the fœtus so soon as it is born, aye,

before it is born, will suck; doubtless as it had done in the uterus

long before. For I have found by experience that the child delayed in

the birth, and before it has cried or breathed, will seize and suck a

finger put into its mouth. A new-born infant, indeed, is more expert at

sucking than an adult, or than he is himself if he have but lost the

habit for a few days. For the infant does not suck by squeezing the

nipple with his lips as we should, and by suction in the common

acceptation; he rather seems as if he would swallow the nipple, drawing

it wholly into his throat, and with the aid of his tongue and palate,

and chewing, as it were, he milks his mother with more art and dexterity

than an adult could practise. He therefore appears to have learned that

by long custom, and before he saw the light, which we know full well he

unlearns by a very brief discontinuance.

These and other observations of the same kind make it extremely probable

that the chick in ovo is nourished in a twofold manner, namely, by the

umbilical and by the mesenteric veins. By the former he imbibes a

nourishment that is well nigh perfectly prepared, whence the

first-formed parts are engendered and augmented; by the latter he

receives chyle for the structure and growth of the other remaining

parts.

But the reason is perhaps obscure why the same agent should perform the

work of nutrition by means of the same matter in a variety of ways,

since nature does nothing in vain. We shall therefore endeavour to

explain this.

What is taken up by the umbilical veins is the purer and more limpid

part; and the rest of the colliquament in which the fœtus swims is like

crude milk, or milk deprived of its purer portion. The purer part does

not require any of that ulterior concoction of which the remainder

stands in need; and to undergo which it is taken into the stomach, where

it is transmuted into chyle. Similar to this is the crude and watery

milk which is found in the breasts immediately after parturition. The

liquefied albumen of the egg, and the crude or watery milk of the mammæ

seem to have in all respects the same colour, taste, and consistence.

For the first flow of milk is serous and watery, and women are wont to

express water from their breasts before the milk comes white, concocted,

and perfect.

Just as the colliquament found in the crop of the chick is a kind of

crude milk, whilst the same fluid discovered in the stomach is

concocted, white, and curdled; so in viviparous animals, before the milk

is concocted in the mammæ, a kind of dew and colliquament makes its

appearance there, and the colliquament only puts on the semblance of

milk after it has undergone concoction in the stomach. And so it

happens, in Aristotle’s opinion, that the first and most essential parts

are formed out of the purer and thinner portion of the colliquament, and

are increased by the remaining more indifferent portion after it has

undergone elaboration by a new digestion in the stomach. In the same way

are the other less important parts developed and maintained. Thus has

nature, like a fond and indulgent mother, been sedulous rather to

provide superfluity, than to suffer any scarcity of things necessary. Or

it might be said to be in conformity with reason to suppose that the

fœtus, now grown more perfect, should also be nourished in a more

perfect manner, by the mouth, to wit, and by a more perfect kind of

aliment, rendered purer by having undergone the two antecedent

digestions and been thereby freed from the two kinds of excrementitious

matter. In the beginning and early stages, nourished by the

ramifications of the umbilical veins, it leads in some sort the life of

a plant; the body is then crude, white, and imperfect; like plants, too,

it is motionless and impassive. As soon, however, as it begins by the

mouth to partake of the same aliment farther elaborated, as if feeling a

diviner influence, boasting a higher grade of vegetative existence, the

gelatinous mass of the body is changed into flesh, the organs of motion

are distinguished, the spirits are perfected, and motion begins; nor is

it any longer nourished like a vegetable, by the roots, but, living the

life of an animal, it is supported by the mouth.

EXERCISE THE FIFTY-NINTH.

_Of the uses of the entire egg._

Having now gone through the several changes and processes which must

take place in the hen’s egg, in order that it may produce a chick,

Fabricius proceeds to consider the uses of the egg at large, and of its

various parts; nor does he restrict himself to the hen’s egg, but

condescends upon eggs in general. Among other things he inquires:

wherefore some eggs are heterogeneous and composed of different

elements; and others are homogeneous and similar? such as the eggs of

insects, and those creatures that are engendered from the whole egg,

viz. by metamorphosis, and are not engendered from one part of the egg,

and nourished by another part.

I have no purpose myself of entering on a general consideration of eggs

of all kinds and descriptions; I have not yet given the history of all,

but only of the hen’s egg; so that I shall here limit myself to a survey

of the uses of the common hen’s egg, keeping in view the end of all its

actions, which is nothing less than the production and completion of a

new being, as Fabricius has well and truly said.[305]

Among the points having reference to the whole egg, Fabricius speaks of

the form, dimensions, and number of eggs. “The figure of the egg is

round,” he says,[306] “in order that the mass of the chick may be stowed

in the smallest possible space; for the same cause that God made the

world round, namely, that it might embrace all things; and it is from

this, as Galen conceives, that this figure is always felt to be most

agreeable and consonant to nature. Further, as it has no angles exposed

to injury from without, it is, therefore, the safest figure, and the

one best adapted to effect the exclusion of the chick.” It had been well

after such a preface to have assigned satisfactory causes why hen’s eggs

are not spherical, like the eggs of fishes, worms and frogs, but oblong

and pointed; to have shown what there is in them which hinders the

presumed perfection of figure. Now to me the form of the egg has never

appeared to have aught to do with the engenderment of the chick, but to

be a mere accident; and to this conclusion I come the rather when I see

such diversities in the shape of the eggs of different hens. They vary,

in short, in conformity with the variety that obtains among the uteri of

different fowls, in which, as in moulds, they receive their form.

Aristotle,[307] indeed, says that the longer-shaped eggs produce

females, the rounder males. I have not made any experiments upon this

point myself. But Pliny[308] asserts, in opposition to Aristotle, that

the rounder eggs produce females, the others males. Now were there any

certainty in such statements, either in one way or the other, some hens

would always produce males, others always females, inasmuch as the eggs

of the same hen are in many instances always of one figure, namely,

either much rounded or acutely pointed. Horace[309] thought that the

oblong eggs, as being the more perfect and better concocted, and

therefore the better flavoured, produced males.

I willingly pass by the reasons alleged by Fabricius for the form of

eggs, as being all irrelevant.

The size of an egg appears to bear a proportion to the size of the fœtus

produced from it; large hens, too, certainly lay large eggs. The

crocodile, however, lays eggs the size of those of the goose; nor does

any animal attain to larger dimensions from a smaller beginning. It

would seem, too, that the size of the egg and the quantity of matter it

contained had some connexion with its fecundity, inasmuch as the very

small eggs called centenines are all barren.

The number of eggs serves the same end as abundance of conceptions among

viviparous animals--they secure the perpetuity of the species. Nature

appears to have been particularly careful in providing a numerous

offspring to those animals which, by reason of their pusillanimity or

bodily weakness, hardly defend themselves against the attacks of

others; she has counterbalanced the shortness of their own lives by the

number of their progeny. “Nature,” says Pliny,[310] “has made the timid

tribes among birds more fruitful than the bold ones.” All generation as

it is instituted by nature for the sake of perpetuating species, so does

it occur more frequently among those that are shorter-lived and more

obnoxious to external injury lest their race should fail. Birds that are

of stronger make, that prey upon other creatures, and therefore live

more securely and for longer terms scarcely lay more than two eggs once

a year. Pigeons, turtle and ring-doves, that lay but a couple of eggs,

make up for the smallness of the number by the frequency of laying, for

they will produce young as often as ten times in the course of a year.

They therefore engender greatly although they do not produce many at a

time.

EXERCISE THE SIXTIETH.

_Of the uses of the yelk and albumen._

“An egg,” says Fabricius,[311] “properly so called, is composed of many

parts, because it is the organ of the engenderer, and Galen everywhere

insists on the constitution of an organ as implying multiplicity of

parts.” But this view leads us to ask whether every egg must not be

heterogeneous, seeing that every egg is organic? And every egg, indeed,

even that of the fish and insect, appears to be composed of several

different parts,--membranes, coverings, defences; nor is the included

matter by any means without diversity of constitution in different

parts.

Fabricius agrees farther, and correctly, with Galen, when he says:[312]

“Some parts of the egg are the chief instruments of the actions that

take place in it, others may be styled necessary,--without them no

actions could take place; others exist that the action which takes place

may be better performed; others, in fine, are destined for the safety

and preservation of all of these.” But he is mistaken when he says: “If

we speak of the prime action, which is the generation of the chick, the

chief cause of this is the semen and the chalazæ, these two being the

prime cause of the generation of the chick, the semen being the

efficient cause, the chalaza the matter only.” Now according to the

opinion of Aristotle, it must be allowed that that which generates is

included in the egg; but Fabricius denies that the semen of the cock is

contained in the egg.

Nor does he wander less wide of the mark when he speaks of the chalazæ

as the matter from which, by the influence of the semen galli, the chick

is incorporated. For the chick is not produced either from one or the

other, nor yet from both of the chalazæ, as we have shown in our

history. Neither is the generation of the chick effected by

metamorphosis, nor by any new form assumed and division effected in the

chalazæ, but by epigenesis, in the manner already explained. Nor are the

chalazæ especially fecundated by the semen of the male bird, but the

cicatricula rather, or the part which we have called the eye of the egg,

from which, when it enlarges, the colliquament is produced, in and from

which, subsequently, the blood, the veins, and the pulsating vesicles

proceed, after which the whole body is gradually formed. Moreover, on

his own admission, the semen of the cock never enters the uterus of the

hen, and yet it fecundates not only the eggs that are already formed,

but others that are yet to be produced.

Fabricius refers the albumen and vitellus to the second action of the

egg, which is the nutrition and growth of the chick. “The vitellus and

albumen,” he says,[313] “are in quantity commensurate with the perfect

performance of this action, and with the due development and growth of

the chick. The shell and membranes are therefore the safety of the whole

of the egg as well as the security of its action. But the veins and

arteries which carry nourishment are organs without which the action of

the egg, in other words, the growth and nutrition of the chick, would

not take place.” It is uncertain, however, whether the umbilical vessels

of the embryo or the veins and arteries of the mother, whence the egg is

increased, are here to be understood. For a like reason the uterus and

incubation ought to be referred to this last class of actions.

We have to do, then, with the two fluids of the egg, the albumen and the

vitellus; for these, before all the other parts, are formed for the use

of the embryo, and in them is the second action of the egg especially

conspicuous.

The egg of the common hen is of two colours internally, and consists of

two fluids, severally distinct, separated by membranes, and in all

probability of different natures, and therefore having different ends to

serve, inasmuch as they are distinguished by different extensions of the

umbilical veins, one of them proceeding to the white, another to the

yelk. “The yelk and white of the egg are of opposite natures,” says

Aristotle,[314] “not only in colour, but also in power. For the yelk is

congealed by cold; the white is not congealed, but is rather liquefied;

on the contrary, the white is coagulated by heat, the yelk is not

coagulated, but remains soft, unless it be over-done, and is more

condensed and dried by boiling than by roasting.” The vitellus getting

heated during incubation, is rendered more moist; for it becomes like

melted wax or tallow, whereby it also takes up more room. For as the

embryo grows, the albumen is gradually taken up and becomes inspissated;

but the yelk, even when the fœtus has attained perfection, appears

scarcely to have diminished in size; it is only more diffluent and

moist, even when the fœtus begins to have its abdomen closed in.

Aristotle[315] gives the following reason for the diversity: “Since the

bird cannot perfect her offspring within herself, she produces it along

with the aliment needful to its growth in the egg. Viviparous animals

again prepare the food (milk) in another part of their body, namely, the

breasts. Now nature has done the same thing in the egg; but otherwise

than as is generally presumed, and as Alcmæon Crotoniates states it, for

it is not the albumen but the vitellus which is the milk of the egg.”

For as the fœtus of a viviparous animal draws its nourishment from the

uterus whilst it is connected with its mother, like a plant by its roots

from the earth; but after birth, and when it has escaped from the womb,

sucks milk from the breast, and thereby continues to wax in size and

strength, the chick finds the analogue of both kinds of food in the

egg. So that whilst in viviparous animals the uterus exists within the

parent, in oviparous the parent may rather be said to exist within the

uterus (the egg). For the egg is a kind of exposed and detached uterus,

and in it are included in some sort vicarious mammæ. The chick in the

egg, I say, is first nourished by albumen, but afterwards, when this is

consumed, by the yelk or by milk. The umbilical vascular connexion with

the albumen, therefore, when this fluid is used up, withers and is

interrupted when the abdomen comes to be closed, and before the period

of exclusion arrives, so that it leaves no trace of its existence behind

it: in viviparous animals, on the contrary, the umbilical cord is

permanent in all its parts up to the moment of birth. The other canal

that extends to the vitellus, however, is taken up along with this

matter into the abdomen, where being stored, it serves for the support

of the delicate fœtus until its beak has acquired firmness enough to

seize and bruise its food, and its stomach strength sufficient to

comminute and digest it; just as the young of the viviparous animal

lives upon milk from the mammæ of its mother, until it is provided with

teeth by which it can masticate harder food. For the vitellus is as milk

to the chick, as has been already said; and the bird’s egg, as it stands

in lieu both of uterus and mammæ, is furnished with two fluids of

different colours, the white and the yelk.

All admit this distinction of fluids. But I, as I have already said,

distinguish two albumens in the egg, kept separate by an interposed

membrane, the more external of which embraces the other within it, in

the same way as the yelk is surrounded by the albumen in general. I have

also insisted on the diverse nature of these albumens; distinguished

both by situation and their surrounding membranes, they seem in like

manner calculated for different uses. Both, however, are there for ends

of nutrition, the outermost, as that to which the branches of the

umbilical veins are earliest distributed, being first consumed, and then

the inner and thicker portion; last of all the vitellus is attacked, and

by it is the chick nourished, not only till it escapes from the shell

but for some time afterwards.