MAGAZINE OF ZOOLOGY AND BOTANY. ORIGINAL COMMUNICATIONS. I.-Some Remarks on the Study of Zoology, and on the present state of the Science. By the Rev. LEONARD JENYNS, M. A.; F. L. S.; F. Z.S.; &c. NATURAL HISTORY has not only, like most other sciences, made great progress of late years, but it has assumed an importance, to which formerly it in vain attempted to lay claim. It is not, indeed, surprising that so long as it was restricted to collecting plants and animals as mere objects of curiosity, or judged to be of no further consequence than as it admitted of application to economic purposes, it * should be either held up to contempt by the majority of thinking men, or tolerated only so far as it was studied with immediate reference to the ends just alluded to. But there are other grounds upon which, in these days, it is deemed worthy of our regard. The mere collector, indeed, is held in no higher esteem than formerly. The advantages we derive from an acquaintance with those organized beings which are capable of supplying the wants, or augmenting the conveniences of life, are not overlooked, but are considered rather as indirect benefits resulting from the cultivation of this science, than as the immediate objects to which all our researches incline. Natural History is of importance from the effects which it produces, or which at least it is capable of producing, upon the human mind. As a study, it tends equally with all other studies to strengthen the faculties, to fix the attention, and, to a certain extent, to exercise our powers of correct judgment and reasoning. As the particular study of those innumerable beings which people the earth, it has an especial tenden cy to infuse habits of accurate observation; and as one of its objects consists in tracing the complicated relations which these beings bear to one another, it naturally leads the observer to certain first principles of systematic arrangement, which being afterwards transferred to other subjects, are made susceptible of more general application. There are yet further advantages which accrue from the pursuit of this science, sufficient to recommend it, even when followed for its own sake, and apart from all other inducements. The relaxation which it affords the mind, when fatigued with severer studies, or oppressed with anxiety;-the never-failing entertainment which it yields, even in the most retired and solitary spots ;-the charms with which it can invest a country life, diffusing happiness over our leisure hours, and converting every walk into an intellectual treat ;-these are fruits which will not be esteemed lightly, or considered by a reflecting mind as beneath its notice. Above all, we may allude to those devout meditations which this science is calculated to suggest to all such as are alive to the impressions of religion. It tends to uphold that secret communion with the Creator, which Revelation so much encourages. And if this remark has been often made, it only shows how general has been the feeling to which it relates. Strange, indeed, must be the perversion of that mind, which is made neither wiser nor better, by studying the works of Him, whose own wisdom is infinite, and all whose operations tend to good and happiness. We are not disposed to wonder because we find some to whom the study itself fails in affording the same degree of interest which we ourselves derive from it. But to have the thoughts leaning of their own accord to such pursuits;-to be able to expatiate with delight on that immense field of wonders which Nature opens to us;-to trace the workings of the most consummate skill, power, and benevolence;—and yet in our researches to find no room for moral improvement,-no incitement to remember the Great Author of all-we fear this indicates a mind estranged from its own best interests, and but ill qualified for the more exalted employments of a future existence. In what follows, it is proposed to confine our observations to that branch of Natural History termed Zoology. This, in its widest acceptation, may be defined as the science which treats of every thing relating to the structure, functions, history, and classification of animals. Under the head of structure, is included the form and arrangement of the several organs which enter into the composition of the animal body under that of functions, the phenomena exhibited by • See Cuv. Reg. An. Preface, p. xix. these organs, when considered in action and in connection with the living principle. Hence it appears, that Comparative Anatomy and Physiology are properly subordinate departments of Zoology. Nevertheless, from the immensity of the field which is thus let in upon our view, these last may almost be regarded as distinct sciences; and the Zoologist be considered as restricting his enquiries more exclusively to the habits and classification of animals, and to those distinguishing characters by which their different relations are pointed out. Yet, since all natural arrangement is based upon a knowledge of the whole structure, he cannot safely advance on this head any further than the point to which that structure has been revealed by the anatomist. He may succeed in finding certain external signs by which it is possible to discriminate a particular group from all others, but these signs, in order to be of any value, must necessarily be co-ordinate with a given arrangement of the internal organs, which internal organs are therefore assumed as known. It is difficult to form any adequate idea of the large number of facts, which it falls to the province of Zoology, even thus restricted, to record and classify. So various are the forms assumed by different animals ;—so diversified their modes of life,—their habits and economy, -their instincts, whether exerted for the preservation of the individual or for the continuance of the species;—so dispersed the localities in which the yare found resident,-the earth,-the air,-the ocean, -all teeming with their respective inhabitants, and giving rise to a countless series of phenomena ;-so complex too are the affinities by which they are severally related to one another;-that there seems hardly any limit to the enquiries which it becomes necessary to make in order to get acquainted with the details of their history. But our astonishment is excited most, by considering the immense number of species included in the animal kingdom, a number far exceeding that of plants and minerals put together. In an article in the Edinburgh New Philosophical Journal, published in October 1833,* the total number of known living species of animals, is estimated at 78,849. This, however, is probably far below the truth, since, according to Mr Macleay, upwards of 100,000 species of Annulosa alone are already contained in our cabinets. What may be the entire number of species actually existing, in all the several classes combined, it is impossible to conjecture. Perhaps it may be thought that we are by this time nearly acquainted with the larger animals. But let it be remembered that a somewhat similar opinion was entertained by Ray so long Vol. xv. p. 221. Hor. Ent. part ii. p. 468. back as in 1690. The number of known and described species of Beasts, under which term Serpents also were included, was estimated by that naturalist as not above 150; and he added his belief that "not many of any considerable bigness, in the known regions of the world, had escaped the cognizance of the curious." The number of Birds known and described he considered as nearly 500; and the number of Fishes the same; and he supposed that "the whole sum of beasts and birds might exceed by a third part, and fishes by one-half, those known." Now what has been the result of discovery since then with respect to these groups only? The number of Mammalia has been raised from 150 to 1200,† the number of Birds from 500 to 6500; the number of Reptiles, included by Ray amongst his Beasts, has reached to 1500 §; the number of Fish, which he considered the same as that of birds, to 8000.|| But, however large may be the proportion of known to unknown species amongst the vertebrate animals, that proportion must be very different, and in all probability quite insignificant, in the case of the invertebrate. After all one thing is certain; that our lists have, from the earliest times, been gradually extending, in proportion to the increased attention which has been paid to the science; and judging from the immense accessions which they have received during the last fifty years, it is clear that if they continue long to augment in the same ratio, we must be yet at a great distance from the knowledge of the entire number. It may be safely asserted that the number of species left recorded by Linnæus in the twelfth edition of the Systema Naturæ, the date of which is yet upwards of seventy years posterior to that of Ray's work on the Creation, is certainly not one-twentieth part of those we are now acquainted with. With this immense assemblage of beings, and with all their several peculiarities of character and economy, the Zoologist has to treat. Every part of their history calls for his investigation. He must search them out in their native haunts and recesses;-follow them through the several stages of their existence;-observe their habits;-trace the different degrees of resemblance between different species;-and, lastly, from the facts thus accumulated, endeavour to ascend to the knowledge of those general laws upon which depend their affinities and natural classification.-Well might Ray exclaim, with reference • Wisdom of God manifested in the Works of the Creation. Sixth Edition, p. 21. + L'Institut, 1834, p. 138. Edinb. New Phil. Journ. Vol. xv. p. 223. $ Ibid. to such pursuits,-" Here is employment enough for the vastest parts, the most indefatigable industries, the happiest opportunities, the most prolix and undisturbed vacancies." And well might he add, in the words of Seneca,-" Multum adhuc restat operis, multumque restabit, nec ulli nato post mille sæcula præcludetur occasio aliquid adhuc adjiciendi." If we turn from contemplating this extensive field to taking a general view of what has been as yet effected in it, we shall not be surprised at finding the progress of the science to have been very unequal in its different departments. This may be attributed to two causes. One is the natural predilection shown by most observers towards certain branches of Zoology in preference to others; those especially which are calculated to excite notice by reason of the size or beauty of the animals of which they treat. It is this circumstance which has obtained for the Mammalia and Birds so large a share of the attention of naturalists, whilst it has caused the Reptiles and Fish to be comparatively neglected. The same partiality appears in the case of the Invertebrate animals. It is notorious how the departments of Entomology and Conchology have had their respective admirers from the earliest times, and how seldom we have seen, till lately, any desire manifested to investigate the other portions of that immense group. If here and there we find certain individuals who have devoted themselves to the more obscure tribes ;-if Ellis and Lamouroux and a few others have acquired celebrity by their researches into the nature of Corallines and other Zoophytes;-if the name of Müller will be for ever associated with the microscopic Infusoria, and that of Rudolphi with a class of animals from which most other observers would shrink with disgust ;-these men stand as illustrious exceptions to the general indifference shown towards such departments, and shine the more conspicuous from having so few competitors in the same field. It may, however, be remarked that at the present day this source of unequal progress is much on the decline. Naturalists do not now restrict themselves so much as formerly to certain branches of the science. There appears to be an earnest wish to set them all as much as possible upon the same footing, and to bring up from the rear some which had for a long time been neglected and overlooked. But another cause operates yet more extensivel and more unavoidably to retard our knowledge of certain groups of animals, and that is the difficulty which in many instances attends the study of them. We find some whose ordinary place of residence is confined to stations not Wisdom of God in the Creation, &c. p. 173. |