ARTIFICIAL SYSTEMS AND TERMINOLOGY OF ORGANS FROM CESALPINO TO LINNAEUS.
1583-1760.
While botany was being developed in Germany and the Netherlands in the
manner described in the previous chapter, and long before this process
of development reached its furthest point in Kaspar Bauhin, ANDREA
CESALPINO in Italy was laying down the general plan, on which the
further advance of descriptive botany was to proceed in the 17th and
till far into the 18th century; all that was done in the 17th century
in Germany, England, and France towards furthering morphology and
systematic botany was done with a reference to Cesalpino’s principles,
whether these were accepted and made use of, or whether it was sought
to refute them. This connection with Cesalpino became gradually less
close and less obvious, being concealed by new points of view and by
the increase of material for observation; but Cesalpino’s ideas on the
theoretical principles of systematic botany and the nature of plants
appear so plainly, even in the views of Linnaeus, that no one can
read both authors without lighting not unfrequently upon passages in
Linnaeus’ ‘Fundamenta’ or in his ‘Philosophia Botanica,’ which remind
him of Cesalpino, and even upon sentences borrowed from him. As we
saw in Kaspar Bauhin the close of the course of development commenced
by Fuchs and Bock, so we may regard Linnaeus as having built up and
completed the edifice of doctrine founded by Cesalpino.
Cesalpino comes before us, in strong contrast with the simple-minded
empiricism of the German fathers of botany, as the thinker in presence
of the vegetable world. Their main task was the amassing descriptions
of individual plants. Cesalpino made the material gathered by
experience the subject of earnest reflection; he sought especially to
obtain universals from particulars, important principles from sensuous
perceptions; but as his forms of thought were entirely Aristotelian, it
was inevitable that his interpretation of the facts should introduce
into them much that would have to be got rid of subsequently by the
inductive method. Cesalpino differs also from the German botanists in
another respect; he did not rest satisfied with the general impression
produced by the plants, but carefully examined the separate parts and
paid attention to the small and concealed organs; he was the first
who converted observation into real scientific research; and thus
we find in him a remarkable union of inductive natural science and
Aristotelian philosophy, a mixture which gives a peculiar character to
the theoretical efforts of his successors down to Linnaeus.
Cesalpino was moreover much before his time in his mode of
contemplating the vegetable kingdom, seeking always for philosophical
combinations and comprehensive points of view. His work which appeared
in 1583 exercised no perceptible influence on his contemporaries; a
trace of such influence only may be seen in Kaspar Bauhin thirty or
forty years later, while the work of the botanists who followed Bauhin
down to 1670 was confined everywhere to increasing the knowledge of
individual plants. With this object travels were undertaken after 1600
to all parts of the world; many new botanic gardens were added to the
few which had been founded in the 16th century—as at Giessen in 1617,
at Paris in 1620, at Jena in 1629, at Oxford in 1632, at Amsterdam in
1646, at Utrecht in 1650. Instead of endeavouring to embrace with their
labours the whole vegetable kingdom, botanists preferred to devote
themselves to the examination of single districts. This gave rise to
the first local floras (the word flora, however, was first introduced
by Linnaeus in the next century), and of these Germany especially
soon produced a considerable number; a flora of Altorf was published
by Ludwig Jungermann in 1615, of Ingolstadt by Albert Menzel in 1618,
of Giessen by Jungermann in 1623, of Dantzic by Nicolaus Oelhafen in
1643, of Halle by Carl Scheffer in 1662, of the Palatinate by Frank von
Frankenau in 1680, of Leipsic by Paul Ammann in 1675, of Nuremberg by
J. Z. Volkamer in 1700.
But though travel, catalogues in local floras, and the cultivation of
plants in botanic gardens promote knowledge of very varied kind, yet
this remains scattered about among descriptions of plants, until at
last a writer with powers of combination and wider and deeper glance
endeavours to gain some general conclusions from them. Such attempts
we first meet with late in the second half of the 17th century in
Morison, Ray, Bachmann (Rivinus), Tournefort, and others, who took
up Cesalpino’s principles after they had lain neglected for almost a
hundred years, and indeed were almost forgotten by botanists.
In the dearth of higher scientific efforts during this period, the
describing of plants and cataloguing of species prolonged a somewhat
pitiful existence. This describing, a work of great usefulness in the
fathers of German botany, was now become by perpetual repetition a
mechanical labour; all that was to be gained in this way had already
been gained by de l’Obel and Bauhin. This sterility which followed
upon the fruitful beginnings of the 16th century was general; neither
in Germany nor Italy, neither in France nor England, did the botanists
produce anything of importance. The representatives of the science did
not count among the more highly gifted or among the thinkers of their
time; and so content with the minor work of collecting and cataloguing
plants, and with endeavouring to know all plants as far as possible by
name, they lost whatever capacity they may have possessed for more
difficult operations of the mind simply by not attempting them.
There was one man indeed in Germany who studied the vegetable kingdom
in the first half of the 17th century in the spirit of Cesalpino before
him, but who, like Cesalpino, found no honour among contemporary
botanists. This man was the well-known philosopher Joachim Jung,
who invented a comparative terminology for the parts of plants, and
occupied himself with critical enquiries into the theory of the system,
the naming of species and other subjects, embodying their results in a
long array of aphorisms. Free from the genius-stifling burden which the
knowledge of individual species had become, a man possessed of varied
accomplishments and a well-trained mind, Jung was better qualified
than the professed botanists to see what was wanted in botany and
would advance it—a phenomenon more than once repeated in the history
of the science. But his results remained unknown to all except his
immediate pupils, till Ray admitted them into his great work on plants
in 1693, and made them the foundation of his own theoretical botany.
Enriched by Ray’s good morphological remarks, Jung’s terminology passed
to Linnaeus, who adopted it as he adopted every thing useful that
literature offered him, improving it here and there, but impairing its
spirit by his dry systematising manner.
The labours of the botanists of Germany and the Netherlands during
the 17th century, which culminated in Kaspar Bauhin, were not without
important influence upon the development of systematic botany which
began with Cesalpino. When Cesalpino wrote the work which forms an
epoch in the science, he was perhaps unacquainted with the natural
classification of de l’Obel (1576); at least there is nothing in his
book which shows that he had seen it; it appears even as though he had
made the discovery independently, that there is an actual connection of
relationship among plants expressed in their organisation as a whole;
it is at any rate certain that this fact assumed from the first an
entirely different expression in his system from that which it received
at the hands of de l’Obel and Bauhin, inasmuch as he was not guided
by an indistinct feeling for resemblances, but believed that he could
establish on predetermined grounds a system of marks, by which the
objective relationship must be recognised. If Cesalpino was thus in
advance of the German botanists, since he endeavoured to express with
clearness and on principle that which they only felt indistinctly,
he was at the same time treading a dangerous path, and one which led
succeeding botanists astray till the time of Linnaeus,—the path which
must always lead to artificial classifications, since the natural
system can never be laid down upon _a priori_ principles of division.
Through this labyrinth, in which botanists down to Linnaeus wandered
fruitlessly hither and thither, there remained one guide consistently
pointing to the goal to be attained, namely, the feeling for natural
affinity first vividly apprehended by the German botanists, and
expressed by them to some extent in their classifications. And when at
last Linnaeus and Bernard de Jussieu made the first feeble attempts
at a natural arrangement, it was the same indistinct perception which
asserted itself in them as in de l’Obel and Bauhin, and enabled them to
see that the path hitherto trodden could only lead astray.
The period in the development of descriptive botany which begins with
Cesalpino and reaches to Linnaeus may accordingly be perhaps best
characterised by saying, that botanists sought to do justice to natural
affinities by means of artificial classifications, till at length
Linnaeus clearly perceived the contradiction involved in this method
of proceeding. But inasmuch as Linnaeus left it to the future to work
out the natural system, and arranged the plants which he described in
a confessedly artificial manner, he so far marks rather the close of a
previous condition of the science than the beginning of modern botany.
These introductory observations will have supplied the reader with the
thread which will guide him through the following account of the more
prominent points in the history of botanical science from Cesalpino to
Linnaeus.
The often-quoted work of Andrea Cesalpino[17], ‘De plantis libri XVI,’
appeared in Florence in the year 1583. If the value of the contemporary
German botanists lies pre-eminently in the accumulation of descriptions
of individual plants, and these, it is true, occupy fifteen books of
Cesalpino’s work, it is on the contrary the introduction in the first
book, a discussion of the general theory of the subject, which in
his case is of much the higher importance for the history of botany.
This contains in thirty pages a full and connected exposition of the
whole of theoretical botany, and though based on broad and general
views is at the same time extremely rich in matter conveyed in a very
concise form. The different branches into which the subject has since
been divided are here united into an inseparable whole; morphology,
anatomy, biology, physiology, systematic botany, terminology are
so closely combined, that it is difficult to explain Cesalpino’s
views on any one more general question without at the same time
touching on a variety of other matters. Three things more especially
characterise this introductory book; first, a great number of new and
delicate observations; secondly, the great importance which Cesalpino
assigns to the organs of fructification as objects of morphological
investigation; lastly, the way in which he philosophises in strictly
Aristotelian fashion on the material thus gained from experience. If
this treatment has produced a work beautiful in style and fascinating
to the reader, if the whole subject is vivified by it while each
separate fact gains a more general value, it is on the other hand
apparent that the writer is often led astray by the well-known elements
of the Aristotelian philosophy, which are opposed to the interests of
scientific investigation. Mere creations of thought, the abstractions
of the understanding, are treated as really existent substances,
as active forces, under the name of principles; final causes appear
side by side with efficient; the organs and functions of the organism
exist either _alicujus gratiâ_ or merely _ob necessitatem_; the whole
account is controlled by a teleology, the influence of which is the
more pernicious because the purposes assumed are supposed to be
acknowledged and self-evident, plants and vegetation being conceived of
as in every respect an imperfect imitation of the animal kingdom. It
was moreover a necessary consequence of the treatment of his material
adopted by Cesalpino, that his ignorance of the sexuality of plants
and of the use of leaves as organs of nutrition led him to false and
mischievous conclusions; this defect of knowledge would have been of
less importance in a purely morphological consideration of plants, as
we shall see presently in Jung; but with Cesalpino morphological and
physiological considerations are so mixed up together, that a mistake
in the one direction necessarily involved mistakes in the other.
These remarks on Cesalpino’s method may be illustrated by some examples
tending to show how closely he attaches himself to Aristotle, and
how certain Aristotelian conceptions, the origin of which has not
been sufficiently regarded, passed through him into later botanical
speculation. We shall recur in the History of Physiology to Cesalpino’s
views on nutrition, and to his rejection of the doctrine of sexuality
in plants.
‘As the nature of plants,’ so begins Cesalpino’s book, ‘possesses
only that kind of soul by which they are nourished, grow, and produce
their like, and they are therefore without sensation and motion in
which the nature of animals consists, plants have accordingly need of
a much smaller apparatus of organs than animals.’ This idea reappears
again and again in the history of botany, and the anatomists and
physiologists of the 18th century were never weary of dilating on
the simplicity of the structure of plants and of the functions of
their organs. ‘But since,’ continues Cesalpino, ‘the function of
the nutritive soul consists in producing something like itself, and
this like has its origin in the food for maintaining the life of the
individual, or in the seed for continuing the species, perfect plants
have at most two parts, which are however of the highest necessity; one
part called the root by which they procure food; the other by which
they bear the fruit, a kind of foetus for the continuation of the
species; and this part is named the stem (‘caulis’) in smaller plants,
the trunk (‘caudex’) in trees.‘
This in the main correct conception of the upright stem as the
seed-bearer of the plant was also long maintained in botany. We should
observe also that the production of the seed is spoken of as merely
another kind of nutrition, a notion which afterwards prevented Malpighi
from correctly explaining the flower and fruit, and in a modified
form led Kaspar Friedrich Wolff in 1759 to a very wrong conception
of the nature of the sexual function. The next sentence in Cesalpino
takes us into the heart of the Aristotelian misinterpretation of the
plant, according to which the root answers to the mouth or stomach,
and must therefore be regarded in idea as the upper part although it
is the lower in position, and the plant would have to be compared with
an animal set on its head, and the upper and lower parts determined
accordingly: ‘this part (the root) is the nobler (‘superior’) because
it is prior in origin and sunk in the ground; for many plants live by
the roots only after the stem with the ripe seeds has disappeared; the
stem is of less importance (‘inferior’) although it rises above the
ground; for the excreta, if there are any, are given off by means of
this part; it is, therefore, with plants as with animals as regards the
expressions ‘pars superior’ and ‘inferior.’ When indeed we take into
consideration the mode of nourishment, we must define the upper and
the lower in another way; since in plants and animals the food mounts
upward (for that which nourishes is light because it is carried upwards
by the heat), it was necessary to place the roots below and to make the
stem go straight upwards, for in animals also the veins are rooted in
the lower part of the stomach, while their main trunk ascends to the
heart and the head.’ Here, in genuine Aristotelian fashion, the facts
are forced into a previously constructed scheme.
Cesalpino’s discussion of the seat of the soul in plants is of special
interest in connection with certain views of later botanists. ‘Whether
any one part in plants can be assigned as the seat of the soul, such
as the heart in animals, is a matter for consideration—for since the
soul is the active principle (‘actus’) of the organic body, it can
neither be ‘tota in toto’ nor ‘tota in singulis partibus,’ but entirely
in some one and chief part, from which life is distributed to the
other dependent parts. If the function of the root is to draw food
from the earth, and of the stem to bear the seeds, and the two cannot
exchange functions, so that the root should bear seeds and the shoot
penetrate into the earth, there must either be two souls different in
kind and separate in place, the one residing in the root, the other in
the shoot, or there must be only one, which supplies both with their
peculiar capabilities. But that there are not two souls of different
kinds and in a different part in each plant may be argued thus; we
often see a root cut off from a plant send forth a shoot, and in like
manner a branch cut off send a root into the ground, as though there
were a soul indivisible in its kind present in both parts. But this
would seem to show that the whole soul is present in both parts, and
that it is wholly in the whole plant, if there were not this objection
that, as we find in many cases, the capabilities are distributed
between the two parts in such a way that the shoot, though buried in
the ground, never sends out roots, for example in Pinus and Abies, in
which plants also the roots that are cut off perish.’ This, he thinks,
proves that there is only one soul residing in root and stem, but that
it is not present in all the parts; in a further discussion he seeks
to discover the true seat of the soul. He points out an anatomical
distinction between the shoot and the root; the root consists of the
rind and an inner substance which in some cases is hard and woody,
in others soft and fleshy. In the stem on the other hand there are
three constituent parts; outside the rind, inside the pith, between
the two a body which in trees is called the wood. This, on the whole,
correct distinction between stem and root is followed by a thoroughly
Aristotelian deduction.
‘Since then in all creatures’ (we must remark, that this is assuming
a point which has yet to be proved in the case of the half of living
creatures) ‘nature conceals the principle of life in the innermost
parts, as the entrails in animals, it is reasonable to conclude that
the principle of life in plants is not in the rind, but is more deeply
hidden in the inner parts, that is, in the pith, which is found in the
stem and not in the root. That this was the opinion of the ancients
we may gather from the name, for they called this part in plants the
heart (‘cor’), or brain (‘cerebrum’ or ‘matrix’), because from this
part in some degree the principle of foetification (the formation of
the seed) is derived.’ Here we see why the seed must, according to
Cesalpino, have its origin in the pith; the idea was loyally repeated
after him by Linnaeus, as we shall see hereafter. The argument, which
is a long one, ends with the sentence: ‘There are then two chief
parts in plants, the root and the ascending part; therefore the most
suitable spot for the heart of plants seems to be in the central part,
namely, where the shoot joins on to the root. There appears also at
this spot a certain substance differing both from the shoot and from
the root, softer and more fleshy than either, for which reason it is
usually called the cerebrum; it is edible in many plants while they
are young.’ We shall see below how important a part this seat of the
soul of the plant, brought to light with such difficulty and with
all appliances of scholasticism, is intended to play in Cesalpino’s
system, and how by this _a priori_ path he was led to the use of the
position of the embryo in the seed as his principle of division. It
may be remarked here that the point of union between the root and the
stem, in which Cesalpino placed the seat of the plant-soul, afterwards
received the name of root-neck (collet); and though the Linnaean
botanists of the 19th century were unaware of what Cesalpino had proved
in the 16th, and did not even believe in a soul of plants, they still
entertained a superstitious respect for this part of the plant, which
is really no part at all; and this, it would seem, explains the fact,
that an importance scarcely intelligible without reference to history
was once attributed to it, especially by some French botanists. To
return once more to Cesalpino’s ‘cor,’ he is not much troubled by the
circumstance that plants can be reproduced from severed portions; in
true Aristotelian manner he says that although the principle of life
is actually only one, yet potentially it is manifold. Ultimately a
‘cor’ is found in the axil of every leaf, by which the axillary shoot
is united with the pith of the mother-shoot, and finally, in direct
contradiction to the previous proof that the crown of the root is the
seat of the plant-soul, it is distinctly affirmed in Chapter V that the
soul of plants is in some sense diffused through all their parts.
The theoretical introduction to his excellent and copious remarks on
the parts of fructification may supply another example of Cesalpino’s
peripatetic method: ‘As the final cause (‘finis’) of plants consists
in that propagation which is effected by the seed, while propagation
from a shoot is of a more imperfect nature, in so far as plants do
exist in a divided state, so the beauty of plants is best shown in the
production of seed; for in the number of the parts, and the forms and
varieties of the seed-vessels, the fructification shows a much greater
amount of adornment than the unfolding of a shoot; this wonderful
beauty proves the delight (‘delitias’) of generating nature in the
bringing forth of seeds. Consequently as in animals the seed is an
excretion of the most highly refined food-substance in the heart, by
the vital warmth and spirit of which it is made fruitful, so also
in plants it is necessary that the substance of the seeds should be
secreted from the part in which the principle of the natural heat lies,
and this part is the pith. For this reason, therefore, the pith of the
seed (that is, the substance of the cotyledons and of the endosperm)
springs from the moister and purer part of the food, while the husk
which surrounds the seed for protection springs from the coarser part.
It was unnecessary to separate a special fertilising substance from the
rest of the matter in plants, as it is separated in animals which are
thus distinguished as male and female.‘
This last remark and some lengthy deductions which follow are intended
to prove, after the example of Aristotle, the absence and indeed the
impossibility of sexuality in plants, and accordingly Cesalpino goes
on to compare the parts of the flower, which he knew better than his
contemporaries, with the envelopes of the ova in the foetus of animals,
which he regards as organs of protection. Calyx, corolla, stamens,
and carpels are in his view only protecting envelopes of the young
seed, as the leaves are only a means of protecting the young shoots.
Moreover by the word flower (‘flos’) Cesalpino understands only those
parts of the flower which do not directly belong to the rudiment of
the fruit, namely, the calyx, the corolla, and the stamens. This must
be borne in mind if we would understand his theory of fructification,
and especially his doctrine of metamorphosis. We must also note, that
by the expression pericarp he understands exclusively juicy edible
fruit-envelopes, though at the same time pulpy seed-envelopes inside
the fruit pass with him for pericarps. The parts of his flower are
the ‘folium,’ which evidently means the corolla, but in certain
cases includes also the calyx; the ‘stamen,’ which is our style; and
the ‘flocci,’ our stamens. We see that Cesalpino uses the same word
‘folium’ without distinction for calyx, corolla, and ordinary leaves;
just as he, and Malpighi a hundred years later, unhesitatingly regarded
the cotyledons as metamorphosed leaves. In fact the envelopes of the
flower and the cotyledons approach so nearly to the character of
leaves, that every unprejudiced eye must instinctively perceive the
resemblance; and if doubts arose on this point in post-Linnaean times,
it was only a consequence of the Linnaean terminology, which neglected
all comparative examination.
Moreover the doctrine of metamorphosis appears in a more consistent
and necessary form in Cesalpino than in the botanists of the 19th
century before Darwin; it flows more immediately from his philosophical
views on the nature of plants, and appears therefore up to a certain
point thoroughly intelligible. We may also consider as part of this
doctrine in Cesalpino the view that the substance of the seed (embryo
and endosperm) arises from the pith, because the pith contains the
vital principle[18], and as the pith in the shoot is surrounded for
protection by the wood and the bark, so the substance of the seed
is surrounded by the woody shell, and by the bark-like pericarp or
by a fruit-envelope answering to a pericarp. According to Cesalpino
therefore the substance of the seed with its capability of development
springs from the pith, the woody shell from the wood, the pericarp
from the rind of the shoot. The difficulty which arises from this
interpretation, namely, that in accordance with his theory the parts
of the flower also, the calyx, the corolla, and the stamens ought to
spring from the outer tissues of the shoot, he puts aside with the
remark (p. 19) that these parts of the flower are formed when the
pericarp is still in a rudimentary state; that the pericarp is only
fully developed after these parts have fallen off, and that they are so
thin that there is nothing surprising in this view of the matter. We
see in Cesalpino’s doctrine of metamorphosis without doubt the theory
of the flower afterwards adopted by Linnaeus, though in a somewhat
different form. That Linnaeus himself regarded the theory ascribed to
him on the nature of the flower as the opinion of Cesalpino also,
is shown in his ‘Classes Plantarum,’ where in describing Cesalpino’s
system he says: ‘He regarded the flower as the interior portions of
the plant, which emerge from the bursting rind; the calyx as a thicker
portion of the rind of the shoot; the corolla as an inner and thinner
rind; the stamens as the interior fibres of the wood, and the pistil
as the pith of the plant.’ It may be observed however that this was
not exactly what Cesalpino says; but it is nevertheless certain that
Linnaeus’ own view as given in these words was intended to reproduce
that of Cesalpino; and if it does not do this exactly, there is no
essential difference in principle between the two, Linnaeus’ conception
being perhaps a more logical statement of Cesalpino’s meaning.
Cesalpino’s doctrine of metamorphosis appears plainly on another
occasion also; he says, that we do not find envelopes, stamens, and
styles in all flowers; the flowers change in some cases into another
substance, as in the hazel, the edible chestnut, and all plants that
bear catkins; the catkin is in place of a flower, and is a longish
body arising from the seat of the fruit, and in this way fruits appear
without flowers, for the styles (‘stamina’) form the longer axis of
the catkin (‘in amenti longitudinem transeunt’), while the leafy parts
and the stamens are changed into its scales. All this shows that the
notion of a metamorphosis, of which we find intimations as early
as Theophrastus, was a familiar one to Cesalpino, and it fitted in
perfectly with his Aristotelian philosophy, while Goethe’s doctrine on
the same subject is equally scholastic in its character, and therefore
looks strange and foreign in modern science. It has already been
observed that Cesalpino includes only the envelopes and stamens under
the word flower, and distinguishes the rudiments of the fruit from
them; therefore he says that there are plants which produce something
in the shape of a catkin, without any hope of fruit, for they are
entirely unfruitful; but those which bear fruit have no flowers, as
Oxycedrus, Taxus, and among herbs Mercurialis, Urtica, Cannabis, in
which the sterile plants are termed male, the fruitful female. Thus he
distinguished the cases which we now call dioecious from the previously
mentioned monoecious plants, among which he reckons the maize.
All this may serve to give the reader some idea, though a very
incomplete one, of Cesalpino’s theory; to do him justice, it would be
necessary to give a full account of his very numerous, accurate, and
often acute observations on the position of leaves, the formation of
fruit, the distribution of seeds and their position in the fruit, of
his comparative observations on the parts of the fruit in different
plants, and above all of his very excellent description of plants with
tendrils and climbing plants, of those that are armed with thorns
and the like. Though there is naturally much that is erroneous and
inexact in his accounts, yet we have before us in the chapters on
these subjects the first beginning of a comparative morphology, which
quite casts into the shade all that Aristotle and Theophrastus have
said on the subject. But the most brilliant portions of his general
botany are contained in the 12th, 13th, and 14th chapters, in which
he gives the outlines of his views on the systematic arrangement of
plants; to prepare the way for what is to follow, he shows first
that it is better to give up the four old divisions of the vegetable
kingdom, and to unite the shrubs with the trees and the undershrubs
with the herbs. But how these genera are to be distinguished into
species is, he says, hard to conceive, for the multitude of plants is
almost innumerable; there must be many intermediate genera containing
the ‘ultimae species,’ but few are as yet known. He then turns to the
divisions founded on the relations of plants to men. Such groups, he
says, as vegetables and kinds of grain, which are put together under
the name of ‘fruges’ and kitchen-herbs (‘olera’), are formed more
from the use made of them than from the resemblance of form, which we
require; and he shows this by good examples. The discerning of plants,
he continues, is very difficult, for so long as the genera (larger
groups) are undetermined, the species must necessarily be mixed up
together[19]; the difficulty arises from our uncertainty as to the
rules by which we should determine the resemblances of the genera.
While there are two chief parts in plants, the root and the shoot, we
cannot, as it seems, determine the genera and species from the likeness
or unlikeness either of the one or of the other; for if we make a genus
of those plants which have a round root, as the turnip, Aristolochia,
Cyclamen, Arum, we separate generically things which agree together in
a high degree, as rape and radish which agree with the turnip, and the
long Aristolochia which agrees with the round, while at the same time
we unite things most dissimilar, for the Cyclamen and the turnip are
in every other respect of a quite different nature; the same is the
case with divisions which rest merely on differences in the leaves and
flowers.
In pursuing these reflections, which have the conception of species
chiefly in view, he arrives at the following proposition: That
according to the law of nature like always produces like, and that
which is of the same species with itself.
All that Cesalpino says on systematic arrangement shows that he was
perfectly clear in his own mind with regard to the distinction between
a division on subjective grounds, and one that respects the inner
nature of plants themselves, and that he accepted the latter as the
only true one. He says, for instance, in the next chapter: ‘We seek
out similarities and dissimilarities of form, in which the essence
(‘substantia’) of plants consists, but not of things which are merely
accidents of them (‘quae accidunt ipsis’).’ Medicinal virtues and other
useful qualities are, he says, just such accidents. Here we see the
path opened, along which all scientific arrangement must proceed, if
it is to exhibit real natural affinities; but at the same time there
is a warning already of the error which beset systematic botany up to
Darwin’s time; if in the above sentence we substitute the word idea
for that of substance, and the two expressions have much the same
meaning in the Aristotelian and Platonic view of nature, we recognise
the modern predarwinian doctrine, that species, genera, and families
represent ‘ideam quandam’ and ‘quoddam supranaturale.’
Pursuing his deductions, Cesalpino next shows, that the most important
divisions, those of woody plants and herbs, must be maintained in
accordance with the most important function of vegetation, that of
drawing up the food through root and shoot; this division passed from
the first and later on up to the time of Jung for an unassailable
dogma, to which science simply had to conform. The second great
function of plants is the producing their like, and this is effected
by the parts of fructification. Though these parts are only found in
the more perfect forms, yet the subdivisions (‘posteriora genera’) must
be derived in both trees and herbs from likeness and unlikeness in the
fructification. And thus Cesalpino was led, not by induction but by the
deductive path of pure Aristotelian philosophy, to the conclusion, that
the principles of a natural classification are to be drawn from the
organs of fructification; for which conclusion Linnaeus declared him
to be the first of systematists, while he thought de l’Obel and Kaspar
Bauhin, who founded their arrangements on the habit only, scarcely
deserving of notice.
It appears, then, that Cesalpino obtained the subdivisions which he
founded on the organs of fructification from _a priori_ views of the
comparative value of organs, such as run through all Aristotelian
philosophy. Of much interesting matter in the remainder of his
introduction we must mention only that he makes the highest product
of plants to be the fructification, of animals sense and movement,
of man the intellect; and because the latter stands in need of no
special bodily instruments, there is no specific difference in men, and
therefore only one species of man.
In his 14th chapter he gives in broad outline a view of the system
of plants which he founded on the fructification, beginning with the
least perfect; no one who knows the botanical writers of the 17th and
18th centuries will be surprised to find that Cesalpino admits the
doctrine of ‘generatio spontanea’ in the case of the lower plants, and
in a somewhat crude form; this came from the teaching of Aristotle, and
even a hundred years later Mariotte endeavoured to set up a plausible
defence of spontaneous generation on physical grounds even in highly
developed plants.
‘Some plants,’ says Cesalpino, ‘have no seed; these are the most
imperfect, and spring from decaying substances; they have only
therefore to feed themselves and grow, and are unable to produce their
like; they are a sort of intermediate existences between plants and
inanimate nature. In this respect Fungi resemble Zoophytes, which are
intermediate between plants and animals, and of the same nature are the
Lemnae, Lichenes, and many plants which grow in the sea.’
Some on the other hand produce seed, which they form after their
peculiar nature in an imperfect condition, as the mule among animals;
these are of the same nature as mere monstrosities or diseased growths
of other plants, and many occur in the class of grain and bear empty
ears. Cesalpino is evidently speaking of the Ustilagineae, but he
includes also the Orobancheae and Hypocystis, which instead of seed
contain only a powder; and he adds that some of the more perfect plants
are sterile, but they do not belong to this division, because the
peculiarity is confined in their case to individuals.
Some plants bear a substance, a kind of wool, on the leaves, which to
some extent answers to seed, because it serves to propagate the plant;
such plants have neither stem, flower, nor true seed, and the Ferns
are of this kind. We should notice this conclusion from Cesalpino’s
morphology, that plants without true seeds have also no stem; the view
that ferns have no stems continued to be held by later botanists,
though the original reason for it was gradually lost; and those who in
the middle of the 19th century argued still in favour of this opinion,
little suspected that they were endeavouring to establish a dogma of
the Aristotelian philosophy. It is a similar case to that of the crown
of the root mentioned above. But other plants, continues Cesalpino,
produce true seeds; and he proceeds to treat of this division first,
on account of its great extent as comprising all perfect plants. Three
things, he says, contribute especially to the constitution of organs,
the number, position, and shape of the parts; the play of nature in the
composition of fruits varies according to their differences, and hence
arise the different divisions of plants. He then shows how he proposes
to apply these relations to the framing of his system, but his various
points of view may be omitted here, as they can be better and more
shortly gathered from the table below.
Other marks to be derived from roots, stems, and leaves, may be used,
he says, for forming the smaller divisions. Lastly, some marks which
contribute to the constitution neither of the whole plant nor of the
fruit, such as colour, smell, taste, are mere accidents and are due to
cultivation, place of growth, climate, and other causes.
The first of Cesalpino’s sixteen books ends with this general view of
his system. The remaining fifteen books contain about 600 pages of
descriptions of individual plants arranged in fifteen classes; some of
the descriptions are exceedingly minute; the trees come first, and are
followed by the shrubs on account of their affinity (‘ob affinitatem’).
Two things have interfered with the recognition and acceptance of this
system; the omission of a general view to precede the text, and its
appearance in the traditional form of books and chapters, such as we
find in de l’Écluse, Dodoens, and Bauhin, instead of in classes and
orders, though it is true that the headings and introductions to the
several books contain the designations and general characteristics
of the classes described in them. Linnaeus has done good service by
giving in his ‘Classes Plantarum’ a general view of all the systems
proposed before his time, among which he gives the first rank to that
of Cesalpino; he has also pointed out the peculiar characteristics of
each system, and has appended to the old names of the genera those with
which he has himself made us familiar. This invaluable work, which is
a key to the understanding of the efforts that were made in systematic
botany from Cesalpino to Linnaeus himself, will often be referred to
in later pages of this history; it will supply us here with a tabular
view of Cesalpino’s main divisions as precisely formulated by Linnaeus,
which is well worth the space it will occupy, as presenting the first
plan proposed for a systematic arrangement of the vegetable kingdom,
with characters for each division. For the better understanding of
these diagnoses it should be remembered that the ‘cor’ (heart) is the
important point in the seed with Cesalpino, and that it is the place in
the embryo where the radicle and the plumule unite, as has been said
in a former page; Cesalpino himself says somewhat inexactly, the place
from which the cotyledons spring.
The characters of the classes are given, for brevity’s sake, in Latin.
ARBOREAE
(Arbores et frutices).
I. Corde ex apice seminis. Seminibus saepius solitariis (e.g. Quercus,
Fagus, Ulmus, Tilia, Laurus, Prunus).
II. Corde e basi seminis, seminibus pluribus (e.g. Ficus, Cactus,
Morus, Rosa, Vitis, Salix, Coniferae, etc.).
HERBACEAE
(Suffrutices et herbae).
III. Solitariis seminibus. Semine in fructibus unico (e.g. Valeriana,
Daphne, Urtica, Cyperus, Gramineae).
IV. Solitariis pericarpiis. Seminibus in fructu pluribus, quibus est
conceptaculum carnosum, bacca aut pomum (e.g. Cucurbitaceae, Solaneae,
Asparagus, Ruscus, Arum).
V. Solitariis vasculis. Seminibus in fructu pluribus quibus est
conceptaculum e siccâ materiâ (e.g. various Leguminosae, Caryophylleae,
Gentianeae, etc.).
VI. Binis seminibus. Semina sub singulo flosculo invicem conjuncta, ut
unicum videantur ante maturitatem; cor in parte superiore, quâ flos
insidet. Flores in umbellâ (Umbelliferae).
VII. Binis conceptaculis (e.g. Mercurialis, Poterium, Galium,
Orobanche, Hyoscyamus, Nicotiana, Cruciferae).
VIII. Triplici principio (ovary) non bulbosae. Semina trifariam
distributa; corde infra sito, radix non bulbosa (e.g. Thalictrum,
Euphorbia, Convolvulus, Viola).
IX. Triplici principio bulbosae. Semina trifariam distributa; corde
infra sito, radix bulbosa (Large-flowered Monocotyledons).
X. Quaternis seminibus. Semina quatuor nuda in communi sede (Boragineae
and Labiatae).
XI. Pluribus seminibus, anthemides. Semina nuda plurima, cor seminis
interius vergens; flos communis distributus per partes in apicibus
singuli seminis (Compositae only).
XII. Pluribus seminibus, cichoraceae aut acanaceae. Semina nuda
plurima, cor seminis inferius vergens, flos communis distributus per
partes in apicibus singuli seminis (Compositae, Eryngium, and Scabiosa).
XIII. Pluribus seminibus, flore communi. Semina solitaria plurima,
corde interius; flos communis, non distributus, inferius circa fructum
(e.g. Ranunculus, Alisma, Sanicula, Geranium, Linum).
XIV. Pluribus folliculis. Semina plura in singulo folliculo (e.g.
Oxalis, Gossypium, Aristolochia, Capparis, Nymphaea, Veratrum, etc.).
XV. Flore fructuque carentes (Filices, Equiseta, Musci including
Corals, Fungi).
The examples appended by me to the diagnoses show that with the
exception of the sixth, tenth, and fifteenth classes, no one perfectly
represents a natural group of the vegetable kingdom. Most of them
are a collection of heterogeneous objects, and the distinction of
Dicotyledons and Monocotyledons, almost perfectly carried out by
de l’Obel and Bauhin, is to a great extent effaced; the ninth class
certainly contains only Monocotyledons, but not all of them. This
result of great efforts on the part of a mind so well trained as
Cesalpino’s is highly unsatisfactory. Not a single new group founded
on natural affinities is established, which does not appear already in
the herbals of Germany and the Netherlands. It is characteristic of
the natural system to reveal itself to a certain extent more readily
to instinctive perception than to the critical understanding. We have
seen that Cesalpino intended as far as possible to give expression in
his system to natural affinities, and the final result was a series
of highly unnatural groups, almost every one of which is a collection
of the most heterogeneous forms. The cause of this apparently so
remarkable fact is this, that he believed that he could establish on
predetermined grounds the marks which indicate natural affinities. The
uninterrupted labour of nearly 300 years, starting again and again
from the same principle or practically under its influence, has given
us inductive proof that the path taken by Cesalpino is the wrong one.
And if, while this path was pursued even into the middle of the 18th
century, we see natural groups emerge with increasing distinctness,
it is because the botanist, though on the wrong track, was still
continually gaining better acquaintance with the ground over which he
was wandering, and attained at length to an anticipation of the truer
way.
JOACHIM JUNG[20] was born in Lübeck in the year 1587, and died after an
eventful life in 1657. He was a contemporary of Kepler, Galileo, Vesal,
Bacon, Gassendi, and Descartes. After having been already a professor
in Giessen, he applied himself to the study of medicine in Rostock,
was in Padua in 1618 and 1619, and there, as we may confidently
believe, became acquainted with the botanical doctrines of Cesalpino,
who had died fifteen years before. Returning to Germany, he held
various professorships during the succeeding ten years in Lübeck and
Helmstädt, and became Rector of the Johanneum in Hamburg in 1629. He
occupied himself with the philosophy of the day, in which he appeared
as an opponent of scholasticism and of Aristotle, and also with various
branches of science, mathematics, physics, mineralogy, zoology, and
botany. In all these subjects he displayed high powers as a student
and a teacher, and especially as a critical observer; in botany at
least he was a successful investigator. He was the first in Germany, as
Cesalpino had been in Italy, who combined a philosophically educated
intellect with exact observation of plants.
His pupils were at first the only persons who profited by his botanical
studies, for with his many occupations and a perpetual desire to make
his investigations more and more complete he himself published nothing.
In 1662 his pupil Martin Fogel printed the ‘Doxoscopiae Physicae
Minores,’ a work of enormous compass left in manuscript at the master’s
death, and another pupil, Johann Vagetius, the ‘Isagoge Phytoscopica,’
in 1678. Ray however tells us that a copy of notes on botanical
subjects had already reached England in 1660. The ‘Doxoscopiae’
contains a great number of detached remarks on single plants and on
their distinguishing marks, and propositions concerning the methods and
principles of botanical research,—all in the form of aphorisms which
he had from time to time committed to paper. The number and contents
of these aphorisms show the earnest attention which he bestowed on
the determination of species; he is displeased that so many botanists
devote more time and labour to the discovery of new plants, than to
referring them carefully and logically to their true genera by means
of their specific differences. He was the first who objected to the
traditional division of plants into trees and herbs, as not founded
on their true nature. But how firmly this old dogma was established
is well shown by the fact, that Ray at the end of the century still
retained this division, though he founded his botanical theories on
the ‘Isagoge’ of Jung. Jung was in advance of Cesalpino and his own
contemporaries in repeatedly expressing his doubt of the existence of
spontaneous generation.
The ‘Isagoge Phytoscopica,’ a system of theoretical botany, very
concisely written and in the form of propositions arranged in strict
logical sequence, was a more important work and had more lasting
effects upon the history of botany. We must look more closely into
the contents of this volume, because it contains the foundation of
the terminology of the parts of plants subsequently established by
Linnaeus. Since the matter of the ‘Isagoge’ is produced in Ray’s
‘Historia Plantarum’ in italics, with special mention of the source
from which it is derived, it cannot be doubted that Linnaeus had made
acquaintance with the teaching of Jung as a young man, in any case
before 1738. It is as important as a matter of history to know that
Linnaeus’ terminology is founded on Jung, as it is to learn that his
most general philosophical propositions on botanical subjects are to
be traced to Cesalpino. It will moreover be fully shown in the account
of the doctrine of sexuality that his knowledge of that subject was
derived from Rudolf Jacob Camerarius.
The first chapter of the ‘Isagoge’ discusses the distinction between
plants and animals. A plant is, according to Jung, a living but not
a sentient body; or it is a body attached to a fixed spot or a fixed
substratum, from which it can obtain immediate nourishment, grow and
propagate itself. A plant feeds when it transforms the nourishment
which it takes up into the substance of its parts, in order to replace
what has been dissipated by its natural heat and interior fire. A
plant grows when it adds more substance than has been dissipated,
and thus becomes larger and forms new parts. The growth of plants is
distinguished from that of animals by the circumstance that their
parts are not all growing at the same time, for leaves and shoots
cease to grow as soon as they arrive at maturity; but then new leaves,
shoots, and flowers are produced. A plant is said to propagate itself
when it produces another specifically like itself; this is the idea in
its broader acceptation. We see that here, as in Cesalpino, the idea of
the species is connected with that of propagation. The second chapter,
headed ‘Plantae Partitio,’ treats of the most important morphological
relations in the external differentiation of plants; here Jung adheres
essentially to Cesalpino’s view, that the whole body in all plants,
except the lowest forms, is composed of two chief parts, the root
as the organ which takes up the food, and the stem above the ground
which bears the fructification. Jung, too, draws attention to the
meeting-point of the two parts, Cesalpino’s ‘cor,’ but under the name
of ‘fundus plantae.’
The upper part, or a portion of the plant, is either a stem, a leaf, a
flower, a fruit, or a structure of secondary importance, such as hairs
and thorns. His definition of the stalk and the leaf is noteworthy;
the stalk, he says, is that upper part which stretches upwards in
such a manner, that a back and front, a right and left side, are not
distinguished in it. A leaf is that which is extended from its point
of origin in height, or in length and breadth, in such a manner, that
the bounding surfaces of the third dimension are different from one
another, and therefore the outer and inner surfaces of the leaf are
differently organised. The inner side of the leaf, which is also called
the upper, is that which looks towards the stem, and is therefore
concave or less convex than the other side. One conclusion he draws,
which is a striking one for that time, that the compound leaf is taken
for a branch by inexperienced or negligent observers, but that it may
easily be determined by having an inner and an outer surface, like the
simple leaf, and by falling off as a whole in autumn. He calls a plant
‘difformiter foliata,’ whose lower leaves are strikingly different
from the upper, an idea which Goethe, in the fragment in Guhrauer,
seems to have altogether misunderstood.
In connection with these general definitions, the different forms of
the stem and of the ramification, and the varieties of leaves are
pointed out and supplied with distinctive names, which are for the
most part still in use. The fourth chapter treats of the division
of the stem into internodes; if the stem or branch, says Jung, is
regarded as a prismatic body, the articulations, that is, the spots
where a branch or a leaf-stalk arises, are to be conceived of as
cross-sections parallel to the base of the prism. These spots when they
are protuberant are called knees or nodes, and that which lies between
such spots is an internode.
It is not possible to quote all the many excellent details which follow
these definitions; but some notice must be taken of Jung’s theory of
the flower, which he gives at some length from the 13th to the 27th
chapters. It suffers, as in Cesalpino, from his entire ignorance of
the difference of sexes in plants, which is sufficient to render any
satisfactory definition of the idea of a flower impossible. Like
Cesalpino too he distinguishes the pistil from the flower, instead
of making it a part of the flower. He regards the flower as a more
delicate part of the plant, distinguished by colour or form, or by
both, and connected with the young pistil. Like all botanists up to the
end of the 18th century, he follows Cesalpino in including under the
term fruit both the dry indehiscent fruits which were supposed to be
naked seeds, and any seed-vessel. He differs from him in calling the
stamens ‘stamina,’ and the style ‘stilus,’ but like Cesalpino he uses
the word ‘folium’ for the corolla. He calls a flower perfect only when
it has all these three parts. He afterwards describes the relations of
form and number in the parts of the flower, and among other things he
enunciates the first correct view of the nature of the capitulum in
the Compositae, which Cesalpino quite misunderstood; and he examined
inflorescences and superior and inferior flowers, which Cesalpino
had already distinguished, with more care than they had previously
received. In his theory of the seed he follows Cesalpino, and adds
nothing to him.
There is nothing which more essentially distinguishes the theoretical
botany of Jung, and marks the advance which he made upon Cesalpino’s
views, than the way in which he discusses morphology in as entire
independence as was possible of all physiological questions, and
therefore abstains from teleological explanations. His eye is fixed
on relations of form only, while his mode of treating them is
essentially comparative, and embraces the whole of the vegetable
kingdom that was known to him. Jung certainly learnt much from
Cesalpino; but in rejecting at least the grosser aberrations of the
Aristotelian philosophy and of scholasticism, he freed himself from
the prepossessions of his master, and succeeded in arriving at more
correct conceptions of the morphology of plants. That his mathematical
gifts assisted him in this respect is easy to be gathered from his
definitions as given above, which bring into relief the symmetry
apparent in the forms of stems and leaves. No more profound or apt
definitions were supplied till Schleiden and Nägeli introduced the
history of development into the study of morphology.
While Cesalpino, Kaspar Bauhin, and Jung stand as solitary forms each
in his own generation, the last thirty years of the 17th century are
marked by the stirring activity of a number of contemporary botanists.
While during this period physics were making rapid advances in the
hands of Newton, philosophy in those of Locke and Leibnitz, and the
anatomy and physiology of plants by the labours of Malpighi and Grew,
systematic botany was also being developed, though by no means to
the same extent or with equally profound results, by Morison, Ray,
Bachmann (Rivinus), and Tournefort. The works of these men and of their
less gifted adherents, following rapidly upon or partly synchronous
with each other, led to an exchange of opinions and sometimes to
polemical discussion, such as had not before arisen on botanical
subjects; this abundance of literature, with the increased animation
of its style, excited a more permanent interest, which spread beyond
the narrow circle of the professional adepts. The systematists
above-named endeavoured to perfect the morphology and the terminology
of the parts of plants, and they found ready to their hands in the
works of their predecessors a considerable store of observations and
ideas, upon which they set themselves to work. A very great number
of descriptions of individual plants had been accumulated since the
time of Fuchs and Bock, and the fact of natural affinity had been
recognised in the ‘Pinax’ of Kaspar Bauhin as the foundation of a
natural system; Cesalpino had pointed to the organs of fructification
as the most important for such a system, and Jung had supplied the
first steps to a comparative morphology in place of a mere explanation
of names. The botanists of the last thirty years of the 17th century
could not fail to perceive that the series of affinities as arranged
by de l’Obel and Bauhin could not be defined by predetermined marks
in the way pursued by Cesalpino, nor fashioned in this way into a
well-articulated system. Nevertheless they held fast in principle to
Cesalpino’s mode of proceeding, though they endeavoured to amend it
by obtaining their grounds of division, not as he had done, chiefly
from the organisation of the seed and fruit, but from other parts of
the flower; variations in the corolla, the calyx, and the general
habit were employed to found systems, which were intended to exhibit
natural affinities. And while the true means were thus missed, the end
itself was not clearly and decidedly adhered to; a system was desired
for the purpose of facilitating the acquisition of a knowledge of
the greatest possible number of individual forms; the weight of the
burden caused by the foolish demand that every botanist should know
all described plants, was continually increasing, and naturally led to
seeking some alleviation in systematic arrangement. Excessive devotion
to the describing of plants stood in the way of such a profound study
of the principles of systematic botany as might have led to enduring
results, and even destroyed the very capacity for those difficult
intellectual operations, which were absolutely necessary to build
up a truly natural system on scientific foundations; the wood could
not be seen for the trees. Above all the morphology founded by Jung,
though acknowledged and employed, was not sufficiently developed by the
labours of others to form the foundation of the system in its grander
features,—a reproach which must be made against the systematists of the
succeeding hundred years with few exceptions. How could the botanists
of the 17th century succeed in acquiring a true conception of the
larger groups indicated by natural affinity, when they still held to
the old division into trees and herbs, which Jung had already set
aside and which is opposed to all consistent morphology, and when they
paid so little attention to the structure of the seed and the fruit,
that they commonly treated dry indehiscent fruits as naked seeds, and
were guilty of other and similar mistakes? But if nothing new and good
in principle found its way into systematic botany, much service was
rendered to it in matters of detail. The working out of various systems
helped to show what marks are not admissible in fixing the limits of
the natural groups; the contradiction between the method and aim of the
systematists became in this empirical way continually more apparent,
till at length Linnaeus was able to recognise it distinctly; and this
was beyond doubt a great gain.
To attempt to give an account of all the systematists of England,
France, Italy, Germany, and the Netherlands during this period
would serve only to obscure the subject; all that is historically
important will be brought out more clearly by mentioning those only
who have really enriched systematic botany. Whoever wishes for a more
complete knowledge of all the systems which made their appearance
before Linnaeus will find a masterly account of them in his ‘Classes
Plantarum,’ and another worth consulting in Michel Adanson’s ‘Histoire
de la Botanique’ (Paris, 1864). It is sufficient for our present
purpose to consider more particularly the labours of the four men whose
names have recently been mentioned.
ROBERT MORISON[21], who was born in Aberdeen in 1620 and died in
London in 1683, was the first after Cesalpino and Bauhin who devoted
himself to systematic botany, that is, to founding and perfecting the
classification of plants. He was reproached by his contemporaries
and successors with having borrowed without acknowledgment from
Cesalpino; this was an exaggeration. Morison commenced his efforts as
a systematist with a careful examination of Kaspar Bauhin’s ‘Pinax’;
there he obtained his conceptions of natural relationship in plants;
and if he afterwards founded his own system more peculiarly on the
forms of the fruit, it was in a very different way from that adopted
by Cesalpino. Linnaeus answers the reproach above-mentioned by the
pertinent remark, that Morison departs as far from Cesalpino in this
point as he is inferior to him in the purity of his method. In the year
1669 appeared a work with the characteristic title, ‘Hallucinationes
Kaspari Bauhini in Pinace tum in digerendis quam denominandis plantis,’
which Haller justly calls an ‘invidiosum opus’; for as there are
writers at all times who ungratefully accept all that is good and
weighty in their predecessors as self-evident, while they point with
malicious pleasure to every little mistake which the originator of a
great idea may commit, so Morison has no word of recognition for the
great and obvious merits of the ‘Pinax,’ though such a recognition
was specially due from one whose design was to point out the numerous
mistakes in that work on the subject of affinities. Kurt Sprengel in
his ‘Geschichte,’ ii. p. 30, also suspects with reason that Jung’s
manuscript, which was communicated by Hartlieb to Ray in 1661, was
not unknown to Morison, and in this paper he might certainly have
found much that suited his purposes. Sprengel says well, that the
‘Hallucinationes’ are a well-grounded criticism of the arrangement of
plants, which the Bauhins had chosen; that the writer goes through the
‘Pinax’ page by page, and shows what plants occupy a false position,
and that it is certain that Morison laid the first foundation of a
better arrangement and a more correct discrimination of genera and
species.
His ‘Plantarum umbelliferarum distributio nova,’ Oxford, 1672, shows
considerable advance; it is the first monograph which was intended to
carry out systematic principles strictly within the limits of a single
large family. The very complex arrangement is founded exclusively on
the external form of the fruit, which he naturally terms the seed. It
is the first work in which the system is no longer veiled by the old
arrangement in books and chapters, perspicuity being provided for by
typographical management,—an improvement which de l’Obel, it is true,
made a feeble attempt to introduce a hundred years before. Morison
also endeavours to give a clear idea of the systematic relations
within the family by the aid of linear arrangement, to some extent
the first hint of what we now call a genealogical tree, and a proof
at any rate of the lively conception which he had formed of affinity,
not drawn indeed only ‘ex libro naturae,’ as the title of his book
states, but in principle from Bauhin. Morison’s inability to appreciate
the merits of his predecessors, and to believe that when he made a
step in advance the way had ever been trodden before, may be seen in
this work also. One of its merits is, that it contains for the first
time careful representations of separate parts of plants, executed in
copper plate[22]. In 1680 appeared the first volumes of his ‘Historia
plantarum universalis Oxoniensis,’ the third portion of which was
published after his death by Bobart in 1699,—a collection of most of
the plants then known and a large number of new ones with descriptions;
the systematic arrangement in this work is to be seen in Linnaeus’
‘Classes Plantarum.’ If Morison in his criticism of Bauhin displayed
considerable acuteness within narrow circles of affinity, his universal
system on the contrary shows extremely small feeling for affinities
on the large scale; the most different forms are brought together
even in the smaller divisions; the last class of his Bacciferae, for
example, contains genera like Solanum, Paris, Podophyllum, Sambucus,
Convallaria, Cyclamen, a result which is the more surprising as Morison
does not, like Cesalpino, confine himself to single fixed marks, but
has regard also to the habit. On the whole his arrangement as an
expression of natural affinities must be ranked after those of de
l’Obel and Bauhin.
Morison’s merit lay in truth less in the quality of what he did,
than in the fact that he was the first to renew the cultivation of
systematic botany on a comprehensive scale. The number of his adherents
was always small; in Germany Paul Ammann, Professor in Leipsic, adopted
Morison’s views in his ‘Character Plantarum Naturalis’ (1685), and
Paul Hermann, Professor in Leyden from 1679 to 1695, after collecting
plants in Ceylon for eight years, proposed a system founded on that of
Morison, but which can scarcely be called an improvement upon it.
In contrast to Morison, JOHN RAY[23] (1628 to 1705) not only knew how
to adopt all that was good and true in the works of his predecessors,
and to criticise and complete them from his own observations, but could
also joyfully acknowledge the services of others, and combine their
results and his own into a harmonious whole. He wrote many botanical
works; but none display his character as a man and a naturalist better
than his comprehensive ‘Historia Plantarum,’ published in three large
folio volumes without plates in the period from 1686 to 1704. This
work contains a series of descriptions of all plants then known; but
the first volume commences with a general account of the science in
fifty-eight pages, which, printed in ordinary size, would itself make a
small volume, and which treats of the whole of theoretic botany in the
style of a modern text-book. If morphology, anatomy, and physiology,
in which latter subject he relies on the authority of Malpighi and
Grew, are not kept strictly apart in his exposition, yet it is easy to
separate the morphological part, and his theory of systematic botany
is in fact given separately. Jung’s definitions of the subject-matter
of each of the chapters on morphology are first given, and Ray then
adds his own remarks, in which he criticises, expands, and supplements
those of his predecessor. Omitting all that is not his own, and the
anatomical and physiological portions, we will describe some of the
more important results of his studies on system. First and foremost Ray
adopted the idea which Grew had conceived, but in a very clumsy form,
that difference of sex prevails in the vegetable kingdom, and hence
the flower had a different meaning and importance for him from what
it had had for his predecessors, though his views on the subject were
still indistinct. Ray perceived more clearly than Cesalpino that many
seeds contain not only an embryo but also a substance, which he calls
‘pulpa’ or ‘medulla,’ and which is now known as the endosperm, and
that the embryo has not always two cotyledons, but sometimes only one
or none; and though he was not quite clear as regards the distinction,
which we now express by the words dicotyledonous and monocotyledonous
embryo, yet he may claim the great merit of having founded the
natural system in part upon this difference in the formation of the
embryo. He displays more conspicuously than any systematist before
Jussieu the power of perceiving the larger groups of relationship in
the vegetable kingdom, and of defining them by certain marks; these
marks moreover he determines not on _a priori_ grounds, but from
acknowledged affinities; but it is only in the great divisions of
his system that he is thus true to the right course; in the details
he commits many and grievous offences against his own method, as we
shall see below when we come to an enumeration of his classes. Modern
writers have often attributed to Ray the merit of having first taught
the transmutation of species, and of being thus one of the founders
of the theory of descent. Let us see how much truth there is in this
assertion. Though plants, says Ray, which spring from the same seed
and produce their species again through seed, belong to the same
species, yet cases may occur in which the specific character is not
perpetual and infallible. Seeds may sometimes degenerate and produce
plants specifically distinct from the mother-plant, though this may
not often happen, and so there would be a transmutation of species, as
experience teaches. It is true that he considered the statements of
various writers, that Triticum may change into Lolium, Sisymbrium into
Mentha, Zea into Triticum, etc., to be very doubtful, yet there were,
he thought, other cases which were well ascertained; it was in evidence
in a court of law that a gardener in London had sold cauliflower seed
which had produced only common cabbage. It is to be observed, he says,
that such transmutations only occur between nearly allied species and
such as belong to the same genus, and some perhaps would not allow that
such plants are specifically distinct. These words, especially when
judged by Ray’s general views, appear only to express the opinion that
certain inconsiderable variations are possible within a narrow circle
of affinity, especially in cultivated plants. Ray does not speak of
the appearance of new forms, but says that a known form changes into
another already existing and known form, which is the reverse of that
which the theory of descent requires.
In his development of the principles of his system, among other
errors we encounter one that leads to very important consequences in
his application of the dictum, ‘natura non facit saltus,’ which he
interprets as though all affinities must present themselves in a series
that would be represented by a straight line,—an error which has misled
systematists even in recent times, and was first recognised as an
error by Pyrame de Candolle. Ray overlooked the fact that the dictum
holds good even when the affinities arrange themselves in the form of
branching series, that is, after the manner of a genealogical tree.
Much more sound is his remark, that the framing of the true system had
previously been impossible, because the differences and agreements of
forms were not sufficiently known; and another saying of his, that
nature refuses to be forced into the fetters of a precise system, shows
the dawn of the knowledge which afterwards led in Linnaeus to a strict
separation of the natural and artificial systems.