תמונות בעמוד

to natural science, a cumbrous nomen- liar to the species. This great reform clature, by devising an admirable plan has been of very great benefit to the of naming* He divided all living crea- study of natural history. tures into two great series of successive- As has been already remarked, Linly subordinate groups (one series of ani- næus's classification of animals and his mals, the other of plants), the animal classification of plants have not shared and vegetable kingdoms. "He defined the same fate. The former has been his various groups of either kingdom by modified and enlarged, the latter has certain resemblances and differences in been discarded. For this there has been form and structure, and though his ar- a valid reason. Classifications may be rangement of plants has been mainly of many sorts. We may classify any discarded, and his arrangement of ani- one given set of objects in a variety of mals much changed, and further subdi- ways according to the way we choose to vided, yet the principles he introduced consider them. and many parts of his actual classifica- But there are two fundamental differtion have been and will be maintained. ences with respect to classification. An For his reform in nomenclature above arrangement may be intended merely for referred to we owe him hearty thanks. convenient reference, or it may be inTill then, the mode of naming animals tended to group the creatures classified and plants was at once cumbrous and according to their real affinities. A little instructive, a descriptive phrase classification intended merely for conve being often employed to designate a par- nient reference may be made to depend ticular kind.

upon characters arbitrarily chosen and The system of naming which Linnæus easily seen, and which may stand alone devised was binomial system which and not coincide with a number of other is now universally adopted. By it every distinctions.

distinctions. For example, when beasts kind of living creature bears a name were arranged in a group of "quadrumade up of two words. These (like the peds" (having for their common charfamily and Christian names of a man) acter the possession of four limbs), such indicate two things. The word which an arrangement excluded from the group comes first indicates to which smaller whales and porpoises (which are really group or “ genus” the designated ani- most closely related to other beasts), mal belongs. The second word indi- while it included lizards and frogs, which cates which kind or species” (out of are of natures very distinct both from the few or many kinds of which such beasts and from one another. smallest group or

genus” may be com- classification may be made to rest on posed) of the genus the designated ani- distinctive characters, which coincide mal may be. Thus, for example, the with a great number of other distincname borne by the sheep is Ovis aries- tions, and so lead to the association of that is to say, it is the kind aries of the creatures which are really alike, and group, or genus, ovis. The word point- which will be found to present a greater ing out the group to which the animal is

and greater number of common characreferred is termed the “generic'' name ; ters the more thoroughly they are examthe word pointing out the kind is called ined. A system of classification of this the

specific" name-Ovis being the latter kind is called a “ natural system,” name of the genus and aries being pecu- because it represents and leads us di

rectly to understand the inter-relations * Promulgated by him in the tenth edition of of different creatures as they really exist his Systema Naturæ, published at Stockholm in in Nature. 1758.

A natural system has also other ad+ Thus, for example, one kind of bat was called by Seba, “canis volans ternatanus oriente vantages; it not only serves as a memoalis," and a kingfisher is termed "todus viridis ria technica as well as a mere artificial pectore rubro rostro recto."

system may do, but it also serves (since # It is not improbable that Linnæus was it must become modified in details as our influenced in this reform by the then recent knowledge increases) as a register of the introduction of family names into Sweden. His father was the first of his race to take one,

knowledge existing at the time of its and he chose the name Linnæus as his sur? promulgation, and also as a help to dis

covery; for since by such a system

But a


these animals are grouped together by a eloquent descriptions of the animal great number of common characters, it world and his zeal for the discovery of leads us (when any new animal or plant new forms, but still more by his sugcomes under our notice) to seek for cer- gestive speculations. Amongst these tain phenomena when once we have ob- latter may be mentioned his theories of served others with which such expected the earth, of the process of generation, phenomena are, according to our sup- his view as to the relations between the posed classification, associated. Thus a animals of the old world and of the new, natural system serves to guide us in the and, most striking of all, his enunciation path of investigation. Now Linnæus's of the probability that species had been classification of animals was, to a con- transformed and modified. In spite of siderable extent, natural, and therefore much that was erroneous in his ideas has, to a considerable extent, persisted. his suggestions have borne good fruit. But his classification of plants reposed Almost simultaneously with the proupon variations in the more internal mulgation of a natural system of plants, (reproductive) parts of flowers (stamens George Cuvier was laboring to complete and pistil) as other anterior and less cele- a zoological task similar to the botanical brated systems had reposed on the form one effected by Jussieu. Cuvier, availof the colored parts of flowers,* or on ing himself of the work of Linnæus, such parts together with their green en- elaborated his Règne Animal,* and carvelope † (or calyx), or only upon the form ried zoology by his untiring researches of the fruit. The genius of Linnæus and encyclopædic knowledge to the was not, however, blind to the imperfec- highest perfection possible in his day. tion of his own classification, for he him- He did this not only as regards living self proclaimed that a natural system kinds, but also with respect to extinct “was the one great desideratum of bo- species, which he, for the first time, retanical science.

stored in imagination, giving figures of The desideratum was supplied at a what were their probable external forms. memorable era. In 1789 Antony Jussieu. As then, Linnæus, by his nomenclature inaugurated this botanical revolution by and system of zoological classification, publishing his Genera Plantarum, and made one important step in the progress therein that natural system of classifica- of modern biology, so a second step was tion of plants which has since (with effected by the arrangement of all known but small modification) been generally animals and plants, in a truly natural adopted.

system, by Jussieu and Cuvier. The great French naturalist, Buffon, A further advance was at the same did not live to witness the publication time rapidly approaching, for simultaof the last-mentioned work. Had he neously with the perfecting of the knowllived to study it, he might have gained edge of structural anatomy as so many a truer insight into the importance of matters of fact, a movement of deep sigbiological classification, and have en- nificance was stirring the minds of men deavored to improve on Linnæus's sys- in Germany—a movement which resulttem, instead of contenting himself with ed in the birth of what has been called criticising and despising it. In spite of “philosophical anatomy." With this, his defective appreciation of the impɔr: the names of Oken, Goethe, Geoffrey tance of a good arrangement and nomen- St. Hilaire, and Owen are, with others, clature, Buffon greatly aided the prog- indissolubly associated. According to ress of Natural History, not only by his this “philosophical anatomy," it is possible for men, from a judicious study of great perfection by Van Baer* and living creatures, to gather a conception Rathke. The study in question was that of certain formative “ideas” which have of animal development—that is, a study governed the production of all animals of the phases which different animals go and vegetables. These ideas were con- through in advancing from the egg to ceived as either ideas in God or as ideas their adult condition. It had of course existing somehow in a Pantheistic uni- been long known to all that such aniverse. The “ideas” were supposed to mals as the frog and the butterfly undergo be nowhere actually realized in the world great changes during this process, but around us, but to be approximated to in the study of development revealed to us various degrees and ways by the forms the strange fact that animals generally, of living creatures. The naturalists of before birth, also undergo great changes, this school triumphantly refuted the old during which each such creature transinotion that all the structures of living torily resembles the permanent condition beings were sufficiently explained by of other creatures of an inferior grade of their wants. Thus they pointed out the organisation. absurdity of supposing that the bones Philosophical anatomy and the study of the embryo's skull originate in a much of development were both highly prosubdivided condition, in order to facili- vocative of research, tending as they did tate parturition, when the skulls of to destroy conceptions on which men's young birds, which are hatched from minds had previously reposed, without eggs, also arise in a similarly subdivided at the same time substituting any other condition. Many other similar popular satisfactory and enduring mental restinginstances of final causation in animal place. They thus prepared the way for structure they similarly explained away. that great modern advance—the concepSome of the views put forth by leaders tion of organic evolution, or the deof the movement-as, for example, by velopment from time to time of new Oken-were extremely fantastic,* and kinds of animals and plants by ordinary were connected with the philosophic natural processes-a conception the prodreams of Hegel and of Schelling. mulgation and general acceptance of Other of their views, however, were both which constitutes another great epoch in significant and fruitful, for they directed the cultivation of Natural History. special attention to such facts as the But as the Linnæan movement was presence in some animals of rudimentary despised by Buffon, so was philosophical structures. Rudimentary structures are anatomy despised by Cuvier. Each of minute structures which some animals these great naturalists seems to have have (c.g., the wing bones of the New been so attracted by the brilliance of Zealand Apteryx), and which are minia- such faces of the many faceted form of ture representatives of parts which are truth as they clearly saw, that they beof large size and of great use in other came more or less blinded to other of its animals. Other such significant facts faces, in themselves no less brilliant and are those of animal development, as captivating. when Goethe discovered in the skull of But if philosophical anatomy and the the human fætus a separate bone of the theory of Wolff had to encounter strenjaw, which is no longer separate even at uous opposition, still greater was the opbirth, and which, before his time, was position which met the efforts of those supposed only to exist in lower animals. who first asserted organic and specific

* Rivinus, 16gu. + Magnol, 1720. * The first edition of the Règne Animal did | Kamel, 1693.

§ Phil. Bot. 77. not appear till 1817, but a preliminary work in The botanical expert will of course under- one volume, entitled " Tableau Elémentaire de stand that what is due to Antony Jussieu's l'Histoire Naturelle des Animaux," appeared uncle Bernard is not here forgotten ; but how in Paris in 1798. ever great was his merit and preponderant his + His first treatise on fossils was his Memoir share in producing the grand result, it was on Megalonyx, published in 1796. From that none the less by the nephew that these results time he continued to publish memoirs on fossil were embodied and published in the work above forms, till in 1811 his classical work, the “Osreferred to.

semens Fossiles," made its appearance.

Thus fresh interest was lent to a most evolution. important study, which may be said to Before the theory of evolution was have been initiated by Caspar Friedrich distinctly enunciated it had its prophetic Wolff, t, which was further developed by precursors, even as far back as the days Pander and Döllinger, and carried to of Aristotle. In modern times, Buffon, * Thus he represented the teeth as being the

as has been already said, threw out sugfingers and toes of the head.

gestions concerning the transformation + In 1859 in a dissertation as Doctor, at of species, and Goethe, Geoffrey St. Halle, he put forward his Theoria Generationis, embodying very many new and accurate investigations.

Entwickelungs-Geschichte der Thiere," “ Historia Metamorphoseos," 1817. 1827-1837.

Hilaire, and Dr. Erasmus Darwin also selves. Thus Owen * has declared that entertained similar views. But it was “derivation holds that every species not until the beginning of the nineteenth changes in time, by virtue of inherent century that the doctrine of evolution tendencies thereto;" and Theophilus was (in modern times) unequivocally Parsons,t of Harvard University, in put forth. It was so put forth by La- 1860, put forth a similar view. In this marck* in the year 1802. He declared country the same theory was indepenthat all existing animals had been deriv- dently put forward and advocated at ed from antecedent forms according to much length in 1870 f by the author of an innate law of progression, the action the present paper. In the work referred of which had been modified by habit, by to, the objections to “Natural Seleccross-breeding, and by the influence of tion" were fully gone into, s and the climatic and other surrounding condi- theory maintained that external stimuli tions. His views were accepted by few, so act on internal predisposing tendenand encountered much ridicule ; but the cies as to determine by direct seminal gradual modifications of opinion which modification the evolution of new spewere being brought about by philosophi- cific forms. cal anatomy and the study of develop- We may then conceive the evolution ment prepared the way for his more of new specific forms to have been happy successors. After a considerable brought about in one or other of the six interval he was followed by Alfred Wal- following ways. The change may have lace and Charles Darwin, I who attrib- been due : uted the origin of new species to the oc- (1.) Entirely to the action of surcurrence and parental transmission to

rounding agencies upon organoffspring of indefinite minute variations

isms which have merely a pas-no two individuals being ever abso

sive capacity for being indefilutely alike. Such variations they con

nitely varied in all directions, ceived as taking place in all directions,

but which have no positive inbut as being reduced to certain lines by

herent tendencies to vary, the destructive agencies of Nature acting

whether definitely or indefiupon creatures placed in circumstances

nitely. of severe competition, owing to the ten- (2.) Entirely to innate tendencies in dency of every kind of organism to in

each organism to vary in cercrease in a geometrical ratio. This

tain definite directions. destructive action together with its re- (3.) Partly to innate tendencies to sult was termed by these authors “ Nat

vary indefinitely in all direcural Selection," but the whole process

tions, and partly to limiting has been more aptly designated by the

tendencies of surrounding conphrase, “the survival of the survival of the fittest."

ditions, which check variations, The doctrine of evolution, however,

save in directions which haphas been accepted and advocated by

pen accidentally to be favorable other writers, who deny that “Natural

to the organisms which vary. Selection" can be the cause of the origin (4.) Partly to innate tendencies to of species. They say that such origin

vary indefinitely in all direcmust be due to whatever produces indi

tions, and partly to external vidual variation, and ultimately to inher

influences which not only limit ent capacities in the organisms them

but actively stimulate and pro

mote variation. * In his “Researches on the Organization of (5.) Partly to tendencies inherent in the Living Bodies" (1802) ; in his “ Philoso

organisms, to vary definitely in phie Zoologique" (1809) ; and also in the in

certain directions, and partly troduction to his “ Hist. Nat. des Animaux sans Vertebres" (1815).

+ Journal of Linnean Society, vol. iii., July Anatomy of Vertebrates," vol. iii. Longist, 1858 ; and "Natural Selection." Macmillan.

1868. 1871.

† American Journal of Science and Art, July, I Journal of Linnean Society, vol. iii., July 1860. ist, 1858 ; and “ The Origin of Species by Genesis of Species." Macmillan. 1870. Means of Natural Selection." John Murray $ See also “Lessons from Nature.” J. 1859.



to external influences acting plan, of which they constitute diverging only by restriction and limita- manifestations. No à priori reason is tion on variation.

conceivable why such similarities should (6.) Partly to innate tendencies to be necessary, but they are easily expli

vary definitely in certain direc- cable if the animals in question are the tions, and partly to external modified descendants of some ancient influences which, in some re- common ancestor. We here, then, see spects, act restrictively, and in an explanation-possibly complete-of other respects act as a stimulus the theories of philosophical anatomy. to variation.

That curious series of metamorphoses It is this last hypothesis which ap- which constitutes each animal's developpears to have the balance of evidence in ment, as recently explained, also reits favor.

ceives a new explanation if we may reBut whatever view may be accepted gard such changes as an abbreviated as to the mode of evolution, a belief in record or history of the actual transforthe fact of evolution has given an im- mation each animal's ancestors may pulse to natural science the effect of have undergone. Finally, by evolution which can hardly be over-estimated. we can understand the singularly comBy this belief the sciences which relate plex resemblances borne by every adult to life have been all more or less modi. animal and plant to a certain number of fied, for light has been thrown by it on other animals and plants. It is through many curious facts concerning the geo- these resemblances alone that the regraphical and geological distribution of ceived systems of classification of plants animals and plants. The presence of and animals have been possible ; and apparently useless structures-such as such classifications viewed in the light the wing of the Apteryx (before referred of evolution assume the form of gento) or the fetal teeth of whales which ealogical trees of animal and vegetanever cut the gum-become explicable ble descent.

ble descent. We have thus a number as the diminished representatives of large of facts and laws of the most varied kind and useful structures present in their upon

which evolution throws a new more or less remote ancestors.

light, and serves to more or less clearly The curious likenesses which under- explain. Evidently, then, with the aclie superficial differences between animals ceptance of the theory of evolution, the become also explicable through "evolu- natural history of animals and plants

needs to be rewritten from the standThat the skeleton of the arm of man, point thus gained. And though there the wing of the bat, the paddle of the is no finality in science, yet there is whale, and the fore-leg of the horse much reason to suppose that a long should each be formed on the same type period will elapse before any new modiis thus easily to be understood. The fication of biological science occurs as butterfly and the shrimp, different as great as that which has been and is being they are in appearance and mode of effected through the theory in question. life, are yet constructed on one common -Contemporary Review.




The philosopher Epictetus, who had Young sir, at home you have been a school at Nicopolis in Epirus at the at fisticuffs with the man-servant, you end of the first century of our era, thus have turned the house upside-down, you apostrophizes a young gentleman whom have been a nuisance to the neighbors ; he supposes to be applying to him for and do you come here with the comeducation :

posed face of a sage, and mean to sit in * Address delivered to the Eton Literary cise my want of point? You have en

judgment upon the lesson, and to critiSociety.

« הקודםהמשך »