Sept 14, 1 8 76 J 



NATURE 



439 



trust, like happy results. The voyage of the Challenger, though 

 a highly important, and, in many respects, a novel one, is not- 

 withstanding only a unit in a long series which began a century 

 ago, and has been continued at intervals to our own day ; nay, 

 more, since the sailing of the Challenger we have witnessed the 

 departure of another and larger expedition for the accomplish- 

 ment of a still more arduous undertaking. But what I have now 

 to speak of is a matter that will, if I am not mistaken, in after 

 ages characterise the present year as an epoch in the history of 

 our sciences inferior only in importance to that which marked 

 some eighteen or nineteen years ago the promulgation of a 

 reasonable Theory of Evolution by Mr. Darwin and Mr. 

 Wallace. And while it is to the latter of these two naturalists 

 that we owe the boon that has recently been conferred on us, it 

 is unquestionably from the former labours of both — united yet 

 distinct — that the boon acquires its greatest value. Without 

 those far higher, far wider views which the Theory of Evolution 

 enables us to take, the serried array of facts that bristle through- 

 out the two volumes of the "Geographical Distribution of 

 Animals " ^ which Mr. Wallace has just published, would have 

 been but a comparatively meaningless aggregation of statements 

 — the evidence no doubt of labour almost unsurpassed, the accu- 

 mulation of much that is curious and of much that is suggestive, 

 but, taken all in all, as serving to an unintelligible or insignificant 

 end, if to any end whatever that was not misleading. 



As the case is, the result is very different. But I would ask 

 you now. Without the aid afforded by the "Doctrine of Descent," 

 would it have been possible to draw, as Mr. Wallace has so 

 skilfully drawn, those legitimate conclusions from a consideration 

 of the animal life of Java (vol. i. pp. 352, 353), or to arrive at 

 those marvellous results with respect to the past history of Borneo 

 (vol. i. pp. 358, 359), or even to indulge in those daring specula- 

 tions with regard to the origin of the Celebesian fauna (vol. i. 

 pp. 436-438) ? I cite these instances because they are taken 

 from that part of the world on which the author's labours have 

 before shed so much light, and with which his name is imperish- 

 ably associated ; but there is hardly any one of bis summaries 

 that does not place before us material for reflection as astounding. 



While, however, assigning to the theory of evolution the chief 

 glory in giving a real and lasting value to the interpretation of 

 the facts of animal distribution, I must not omit acknowledging 

 the share which physical geography has contributed to that end, 

 especially by its marine surveys, which furnish the zoologist with 

 data as to the depths of seas and oceans, and thereby enable 

 him to judge as to the former extent of land. It is therefore to 

 be expected that voyages like that of the Challenger, when their 

 results have been fully worked out, will still further add to our 

 knowledge in this respect. Again, too, geology (but this follows 

 almost as a matter of course) has in its own line played an equal 

 part. I would that botany could be mentioned in this connec- 

 tion, but here it seems as if the eldest of the biological sciences 

 were not, as she usually is, in advance of the rest ; and Mr. 

 Wallace's suggestion (vol. ii. p. 162), that zoology furnishes a 

 key wherewith many of the difficulties besetting the study of the 

 distribution of plants may be unlocked, will doubtless meet with 

 due attention from botanists. 



Of the care and labour which the author of this work has 

 bestowed upon it, no one here I venture to think, has a better 

 right to speak than myself, because it is not very long ago that 

 I attempted a dissertation on the geographical distribution of a 

 single class of animals.^ Though it was the class with which I 

 am most familiar, and though in my attempt I had the invalu- 

 able assistance of Mr. Wallace's manuscript at my side, which 

 cleared my way through many obstacles, still I found the task 

 one of enormous difficulty, and one which I at times almost 

 repented that I had undertaken ; yet Mr. Wallace has treated 

 not of birds only, as I did, but of mammals, amphibians, reptiles, 

 and freshwater fishes — to say nothing of the most telling families 

 of two orders of insects, with the molluscs so far as they were 

 available for his purpose. There is nothing that in turning over 

 the pages of lliese volumes so much strikes one as the energy 

 they evince oii the part of their author. Those who have been 

 most accustomed to the literature of zoology must admit that 

 there is scarcely any book with which "The Geographical Dis- 

 tribution of Animals " may not, in respect of hard and honest 



1 "The Geographical Distribution of Animals, with a Study of the Rela- 

 tions of Living and Extinct Faunas as Elucidating the Past Changes of the 

 Earth's Surface." By Alfred Russel Wallace. Author of "The Malay 

 Archipelago," &c. 8vo, two vols. London, 1876. 



2 Geographical Distribution of Birds in "Encyclopaedia Britannica,'' 

 Ed. 9, vol. jii., pp. 736-764. 



work, be advantageously compared. It deserves to bear good 

 fruit ; and I am greatly mistaken if it will not do so. From an 

 educational point of view, it can hardly fail to be of the greatest 

 service. Attractive as is the subject to those that know it and see 

 its bearings, the learner has hitherto been repelled from its con- 

 sideration by the want of any work of general compass which 

 would guide his studies, while even few of those treatises which 

 have a particular scope were of much use to him. Mr. Wallace 

 has now placed one in his hands ; and the result we need not 

 try to anticipate. One thing, however, is clear — the distribu- 

 tion of animals can no longer be neglected as a secondary or un- 

 important part of zoology. It only remains for me to add, 

 while thus attempting to set forth the general merits of this 

 learned work, that I by no means pin my faith to all the author's 

 details, or to all his conclusions. Most of the latter may indeed 

 be justified by the present imperfect state of our knowledge ; 

 but it does not follow that they will eventually meet with common 

 acceptance. I must particularly call your attention to the 

 admirably cautious words in which he takes leave of his readers 

 — words that prove him to be thoroughly imbued with the 

 right spirit of a true worker in a progressive branch of study. 

 Mr. Wallace says : — 



" The preceding remarks are all I now venture to offer on the 

 distinguishing features of the various groups of land-animals as 

 regards their distribution and migrations. They are at best but 

 indications of the various lines of research opened up to us by 

 the study of animals from the geographical point of view, and by 

 looking upon their range in space and time as an important 

 portian of the earth's history. . . . Till every well-marked 

 district — every archipelago, and every important island, has all 

 its known species of the more important groups of animals cata- 

 logued on a uniform plan, and with a uniform nomenclature, a 

 thoroughly satisfactory account of the geographical distribution of 

 animals will not be possible." 



And then he goes on to point out that more than this is 

 wanted : — 



" Many of the most curious relations between animal forms 

 and their habitats, are entirely unnoticed, owing to the produc- 

 tions of the same locality never being associated in our museums 

 and collections. A few such relations have been brought to 

 light by modern scientific travellers ; but many more remain to 

 be discovered, and there is probably no fresher or more produc- 

 tive field still unexplored in natural history." 



These coincident variations, he concludes by saying, "have 

 never been systematically investigated. They constitute an un- 

 worked mine of wealth for the enterprising explorer ; and they 

 may not improbably lead to the discovery of some of the hidden 

 laws (supplementary to natural selection) which seem to be re- 

 quired in order to account for many of the external character- 

 istics of animals" (vol. ii. pp. 552, 553). 



And now to follow out the idea with which I began. Having 

 touched on the two chief zoological events of the year, let us see 

 if they do not suggest something that will not be beneath your 

 consideration for the remainder of this address. I have spoken 

 of the certainty of the expedition from which we now welcome 

 our friends being succeeded by others of similar character. We 

 shall hardly be indulging any vain imagination if we ask our- 

 selves what we may look forward to as regards their reports ; 

 and to one point we may perhaps usefully apply ourselves. 



What if a future Challenger shall report of some island, now 

 known to possess a rich and varied animal population, that its 

 present fauna has disappeared ? that its only mammals were feral " 

 pigs, goats, rats, and rabbits — with an infusion of ferrets, intro- 

 duced by a zealous " acclimatizer " to check the superabundance 

 of the rodents last-named, but contenting themselves with the 

 colonists' chickens ? that sparrows and starlings, brought from 

 Europe, were its only land-birds, that the former had propa- 

 gated to such an extent that the cultivation of cereals had ceased 

 to pay — the prohibition of bird-keeping boys by the local school- 

 board contributing to the same effect — and that the latter (the 

 starlings) having put an end to the indigenous insectivorous birds 

 by consuming their food, had turned their attention to the 

 settlers' orchards, so that a crop of fruit was only to be looked 

 for about once in five years — when the great periodical cyclones 

 had reduced the number of the depredators ? that the goats had 

 destroyed one half of the original flora, and the rabbits the rest ? 

 that the pigs devastated the potato-gardens, and yam-grounds ? 

 This is no fanciful picture. I pretend not to the gift of prophecy ; 

 that is a faculty alien to the scientific mind ; but if we may 

 reason from the known to the unknown, from what has beeir and 

 from what is to what will be, I cannot entertain a doubt that 



