תמונות בעמוד
PDF
ePub

a

Again, to know living animals thor- belonging to the other group. The oughly it is necessary also to be acquaint- powers which animals possess cannot be ed with extinct animals, so we cannot satisfactorily understood without have an adequate conception of the knowledge of the corresponding powers world of plants without an acquaintance of plants. Our knowledge, for example, with its fossil forms-forms some of of animal nutrition and reproduction which afford evidence of startling cli- would be very incomplete unless we had matic changes, as do the fossil vines a conception of these processes generally, and magnolias of the Arctic region. and therefore of the modes in which

But it may be asked, if the multitude they take place in plants also. On these of living forms is so great, why should accounts it is desirable that both the the Natural History of plants and ani- great groups of living creatures should mals be treated simultaneously? Has be considered conjointly, and the study not the progress of science been accom- of living organisms treated as one great panied by an increasing division of whole. labor, and is it not wise of naturalists to An objection of an opposite nature devote their whole lives to some special may, however, be made to the plan here group ? To this it may be replied, that advocated. It may be objected that modern science tends both to unite and plants and animals should not be considto separate the several departments ofered separately from minerals, but that inquiry. The area to be explored is so all terrestrial productions should be vast, and contains such rich variety, that treated of as one whole, and their subno human mind can hope to master the stantial composition and powers exhibitwhole study of either animals or plants. ed as diverging manifestations of one On this account some naturalists are no great unity. In support of this objeclonger content with being exclusively tion may be urged that very increasing ornithologists or entomologists, or with inter-relation and cross-dependency bedevoting themselves to single primary tween the sciences which have been just groups of birds or insects, but spend referred to. It may be contended that, their whole time—and wisely so—upon though animals and plants do indeed resome still more subordinate section of quire to be treated as one whole, yet zoology. Nevertheless, such students they do not form a really isolated group should also give time to wider study, for the following reasons. The laws of without which they cannot really under mineral aggregation in crystals are imistand the special groups to which they tated in the growth of certain animals. are devoted.

Such subdivision more- The ultimate constituents of the organic over has, as Goethe remarked, a narrow- and inorganic worlds are the same. The ing tendency. Indeed, the necessity for physical forces-light, heat, and eleceach student to understand various tricity-are both needed by and are given branches of science is constantly increas- off from living organisms, as manifestly ing. A certain knowledge of astronomy by fire-flies, warm-blooded animals, and and chemistry has become necessary to the electric eel. The diverse manifestathe geologist, and of geology and chem- tions of life are thus, it may be said, istry to the biologist. Again, the prog- merely due to the play of physical forces ress of knowledge has more and more upon very complex material conditions. revealed the intimate connection which To this it may be replied that, at least exists between the two great groups of practically, the living world does constiliving creatures-animals and plants. tute a domain apart, and the Natural So intimate, indeed, is this connection History of animals and plants (or Biolonow seen to be that, in spite of the man- gy) a very distinct science, for all that it ifest differences between most animals reposes upon and is intimately connectand plants, the position, or even the ex- ed with the sciences of non-living matistence, of the line which is to divide ter. It may also be contended that these organisms is a matter of dispute. there really is a fundamental distinction It has thus become manifestly impossible between the activities of even the lowest to understand adequately the creatures living creature and all merely physical belonging to one of these groups with- forces. For even if the several separate out a certain acquaintance with those actions of organismis can be performed by inorganic bodies, yet no inorganic phy would be quite out of place in this body displays that combination of forces Essay. Here a single observation must which characterises any living being. suffice. Those who believe that the The very composition, again, of the or- First Cause of all creatures which live ganic world differs strikingly in its com- or have lived is a Divine Intelligence plexity from that of the inorganic. having a certain relation of analogy with

Assuming then, provisionally, that the intelligence of man, must also beanimals and plants may together be rea- lieve that all creatures respond to the sonably separated off from the non-living ideas of such creative Intelligence. world and treated as one whole, we find They must also further believe that in that whole to present remarkable char- so far as the ideas we derive from the acters of both change and permanence. study of creatures are true ideas—that Individual organisms, at longer or short- is, truly correspond with their objects, er intervals, disappear and are replaced such ideas must respond, however imby others like them, and such succession perfectly, to the eternal ideas of such a has in some cases endured for very pro- Divine Intelligence, since things which longed periods. In most cases, how- agree with the same thing must in so far ever, kinds as well as individuals have agree with one another. arisen, had their day and died, and have Remote as such questions may appear been succeeded by kinds more or less to be from the study of Natural History, divergent; and this process of replace they have during the present century ment has occurred again and again. much occupied the attention of distinHas the whole series of successions also guished naturalists. They have also had its beginning, or has vegetable life been the occasion of investigations eternally flourished on our planet and which, as we shall shortly see, have borne eternally nourished race after race of fruit the value of which all scientific men diverse animal tribes ? The answer to now admit. These investigations have this question (as far as it can be answer called forth a new conception as to the ed by Physical Science) is, of course, to whole mass of living creatures, and of be sought in the Natural History, not of their relations one to another—a conorganic beings, but of the earth and other ception which renders inadequate all preplanets of our system. But let it be vious pictures of the world of organic granted that the duration of terrestrial life. life is only, when estimated by sidereal From our present standpoint, that epochs, as the up-growth of a day ; yet world, and indeed the entire universe, measured by any more familiar standard may be not inaptly symbolized by a waits antiquity is such as the imagination terfall, such as that of Terni, with its refuses to picture. More than this : look of changelessness due to unceasing even the various kinds of animals and changes, themselves the result of a perplants have had, and have, at least a rel- manence not at first apparent. The ative constancy and permanence. Na- well-known rainbows above the great ture, as we see it, does not present a clouds of sun-lit spray look like fixed scene of confused and evanescent forms and almost solid structures. Though the in a state of Protean change. Were spectator knows that the same falling such the case our existing classifications water cannot be seen for many seconds, could not have been devised. Our and that the persistence of the elements minds perceive that the living world pos- of color must be even less, yet an imsesses certain permanent characters, and pression of persistence and stability reit suggests conceptions not only of mains which, though in some respects an ' order,” causation,' “ utility, illusion, is not altogether false. Though "purpose,” but also of "types" and the physical elements are fleeting, yet

creative ideas,” to attempt to estimate both the cascade and its iridescent arcs the value of which would be to enter are persistent-ideally in the mind which upon philosophy; for the value to be apprehends them, and really in those assigned to such conceptions depends natural laws and that definite arrangeupon the system of philosophy which ment of conditions which continually any one may deem the more reasonable. reproduce the ceaseless flux accompanyThe advocacy of any system of philoso- ing their persistence.

Similarly the ocean, with its obvious may generate new suns and worlds, like changes of tides and currents, storms the fresh flowers of a new spring. and calms, has been a type of change- But if the image of the ocean as refulness ; and yet viewed in comparison flected in the mind of man has repeatwith the upheavals and depressions of edly changed in the course of ages, this the earth's solid surface there is a rela- is still more the case as regards the starry tive, though by no means absolute, truth vault. A collection of visible divinities; in the words :

a hieroglyphic to be puzzled over by the

soothsayer ; a concentric series of star“Time writes no wrinkle on thy azure brow

studded crystal spheres; and finally, Such as creation's dawn behell, thou rollest

the more and more consistent mind-picnow!"

tures of Copernicus and Galileo, Kepler But science reveals a succession of and Newton ! If it is difficult now to changes far from obvious which have realize the change of view introduced by taken place since the first fluid film con- the discovery of Columbus, it is almost densed from the hot vapor of the earth's. impossible to do so with respect to that primeval atmosphere. Such are, changes which was occasioned by the acceptance in its composition, its temperature and of heliocentric astronomy, and which its living inhabitants, from the time of course rendered a new description of when it swarmed with extinct predeces- the heavens inevitable. sors of our present crabs, cuttle-fishes, These considerations may serve to preand star-fishes ; and afterwards, when pare us for analogous changes with rehuge reptiles dominated in it, till they spect to our present subject-organic yielded place to the whales and dolphins nature. This likewise has not only its of a later epoch, and till at last, after real elements of permanence and change, untold ages, the canoes of the earliest but also its ideal changes, due to the races of mankind began at last to ripple different modes in which it has presentits waters.

ed itself to men's minds at different With the advent of man began a suc- stages of discovery. Such changes rencession of ideal changes. For the der necessary fresh descriptions at sucgrowth of knowledge causes our ideas of cessive epochs, and one such epoch is each part of the universe to alter and that in which we live. grow more exact, just as the aspects of Animals and plants must always, to a objects change as they may be viewed greater or less extent, have occupied the through a succession of less refracting attention of mankind. It is probable and more transparent media. How that a certain amount of pleasure was different was the ancient conception of felt even in primeval times in observing the ocean as a fluid boundary encircling living beings. The child of to-day dethe flat plane of the earth, from that ob- lights in the companionship and obsertained by Columbus when, having trav- vation of animals, and in the childhood ersed an unknown ocean and reached a of the human race animals were regardnew world, he exclaimed Il mondo e ed as objects of interest and curiosity as poco !" To-day deep-sea explorations well as of utility in furnishing food and are giving us new conceptions, and its clothing. That such was the case seems Natural History needs re-writing from a evident from the portraits which have fresh standpoint.

come down to us of the reindeer and the The whole universe of fixed-stars and mammoth (the extinct woolly elephant), nebulæ may also be conceived as a vast traced on bones by the fint-workers, fountain of light and motion. For their contemporaries. though (save for the occasional tempo- Indeed, the earliest of our race could rary brightness of some world in confia- not avoid a certain study of animals the gration, and save for the apparent diur- capture of which they needed for their nal revolution of the heavens) it is ap- food or clothing. But in addition to atparently changeless ; yet reason exhibits tention due to such needs, many pheit to us as an area of ceaseless change. nomena of animal life are well fitted to Indeed, as races of living beings succeed strike a savage mind, and this the more each other, so we may fancy that the from that sharpness of the senses which falling together of worlds and systems the ruder races of men possess. The

earliest hunters must have observed the Egyptian priests long anterior to the scihabits of their prey, and have incident. entific glory of Alexandria. ally noticed in their pursuit peculiarities The Greeks, more happily situate in of other creatures, which were not those their beautiful land, botanically so they pursued, but were related to them wealthy, and which is split up into so as enemies or dependents.

many islands, and has a coast line so irIn temperate regions certain phenomena regular through many estuaries, can of animal and plant life must very early hardly have failed to appreciate organic have forced upon man's attention their nature, seeing that they loved not only regular recurrence, coincidently with human beauty, but that of earth, sea, and that of the seasons. For with the an- sky also. But, however that may be, it nual reappearance of certain constella- is certain that it was there that Natural tions men must have noticed such or History first attained a considerable dederly recurrence of flowers and fruits, velopment under an august master. It and the return of migrating birds. The was congruous that the people who so obtrusive note of the cuckoo, and the early attained a social culmination in quick gliding flight of the swallow, must art, the drama, history, rhetoric, and have early been welcomed as the harbin- poetry, constituting them the models gers of approaching summer.

and teachers of mankind for thousands In this way a series of recurring of years to come, should have also led changes—a cycle of phenomena-must the way in Biological Science. have come to be observed. In other Aristotle, the first-known true man of words, both permanence and change science, must be considered (from his must have been noted as existing simul- knowledge of recondite points of anatotaneously in the organic world.

my, and from his sketch of animal classSuch conceptions must, of course, ification) to have been one who bore have been of the most incomplete and within him in germ the biology of later rudimentary character, since the mind ages. Such a man could not have arisen can only bring back from the observation among a people to whom the investigaof the external world that which it has tion of Nature was new or unwelcome. gained the power of apprehending. The The legal Roman spirit seems to have traveller who is ignorant of history and had little inclination for the study of natural science comes back from impe. Nature, yet in Pliny we meet with the rial Rome or sacred Athens, from the proto-martyr of science.

The great impressive solitude of Carnac or the busy song of Lucretius is full of sympathy quays of Trieste, but little the richer in- with organic life in all its forms; and tellectually for the many instructive ob- poetry like that of the Georgics must jects which have met his unappreciating have been intended for minds alive to gaze. : Thus, with the cultivation or de rustic beauty and the harmonies of rural basement of men's minds, the mental life. images and intellectual conceptions they Whether such incipient scientific culform of Nature necessarily undergo cor- ture as existed in classical times would responding changes, and the surround- or would not, if left to itself, have soon ing conditions of scene and climate must ripened into that of the modern world, also largely influence their interest in, cannot be proved. The fall of the Roand their conceptions of, natural objects. man Empire, however, made retrogres

The ancient Egyptians, enclosed in sion inevitable. It may be that such their narrow limestone valley, bounded retrogression has had its scientific comby desert sands and the hot and riverless pensation. For, judging of the source Red Sea, do not seem to have been fa- by the outcome, the tribes which issued vorably circumstanced for the develop- from the glades of the great Hyrcanian ment of a great love of Nature. Yet forest must have brought with them a their frescoes show that apes, antelopes, deep, innate love of natural beauty. As leopards, giraffes, and other strange the floods of tumultuous invasion subbeasts were objects of careful attention ; sided, and were succeeded by disturband Solomon's taste for natural knowl- ances comparatively local, Teutonic edge may have found its parallel amongst homesteads began to appear on sites which seem to have been in part chosen the action of the sun on mud and in from a love for the picturesque. Soon, other ways, and creatures which were one by one, also arose the monastic cra- erroneously supposed to be hybrids had dles of mediæval civilisation, sometimes also been supposed to have been occanestling in leafy dells by streams or sionally generated. With these exceplakes, sometimes perched on mountain tions, however, all animals were supcrags with difficulty accessible,

posed to have existed unchanged and With the advent of the thirteenth cen- without fresh creations since their first tury came the first pale dawn of that re- formation after the beginning of the naissance which, rapidly maturing, burst world. on the world in its full blaze three cen- The interest felt in all the natural turies later.

sciences continued to increase through It was then that the naturalistic spirit the seventeenth and eighteenth centubegan to assume that predominance ries, and therewith went on a rapid augwhich it has ever since retained. Dis- mentation in the number of known covery on discovery in every department species of animals and plants. of science opened out fresh vistas on all Much gratitude is due from us to the sides to the gaze of eager students, and great compilers of those centuries wh the immensity of the task before inquirers ponderous works were treasure-houses became more manifest to them at each of the natural history of their day. Constep made in advance.

spicuous above all was Aldrovandus, The past also began to acquire a new whose thirteen folios began to appear in significance, for the study of it (as made 1640, to be followed in the next century known in terrestrial deposits) suggested by the richly illustrated folios of Seba. the modern view of the mutability of the Thus the way was gradually prepared earth's surface. No doubt in very early for a decisive step in advance, marking times the occasional discovery of fossil the first great epoch in the modern natushells and bones-disclosed by some ral history of living beings. Such a step land-slip-may have led to vague sur- was the introduction of a good classifimises, as the finding of elephants' bones cation. (many of which so much resembled hu- It is, of course, difficult to acquire, man bones) may have given rise to tales and impossible to retain and propagate, of giants. With the advance from prime- a thorough knowledge of any very nuval to classical times clearer notions merous set of objects, unless they are arose, and Pythagoras (according to systematically grouped according to Ovid) promulgated the most rational some definite plan of classification. On view as to the excavating action of rivers, this account the study of living creatures the upheaval and submergence of land (to the vast number of which attention and similar phenomena.

has been directed stood in especial need But in the Middle Ages these views of some convenient arrangement, if only seem to have faded from view, so that for the purpose of serving as a memoria when in the sixteenth century fossil re- technica. mains began to be collected in Italy and Attempts at a classification of living their significance correctly appreciated, beings had been made by many naturalan important revolution in men's minds ists from Aristotle downwards, and commenced.

amongst the more recent, that of John In spite, however, of the gradually Ray * (1628–1705) may be honorably clearer apprehension of the fact that distinguished. But it was not till 1735 many living forms had become extinct, that a classification was put forward the belief in the fixity of the different which marked that epoch in the study kinds of animals and plants was accept of natural history above adverted to. It ed as a matter of course.

There were,

was promulgated by the publication of however, exceptions to this belief as to the Systema Nature of Linnæus. His fixity which continued to be made, as genius also did away with that obstacle they had been made during the Middle Ages. During those ages creatures,

* See his Methodus plantarum nova, 1682, such as worms and flies, had been sup- and his Animalium quadrupedum et serpentini posed to be spontaneously generated by generis, 1693.

« הקודםהמשך »