NA TURE 



457 



THURSDAY, SEPTEMBER 17, i? 



LVDEKKER'S GEOGRAPHICAL HISTORY OF 

 MAMMALS. 



A Gci\i;raphiai! History of Mammals. By R. Lydekker, 

 B.A., F.R.S., \'.P.G.S., &c. Cambridge Geographical 

 Series. Pp. xii + 400- (Cambridge : University Press, 

 i8g6.) 



1"'HERE can be no doubt about Mr. Lydekker's 

 qualifications to enter on the field of geographical 

 distribution. The author of the excellent treatise on 

 mammals in the " Royal Natural History," after serving 

 an apprenticeship on the Indian Geological Survey, has 

 arranged and catalogued the splendid series of remains 

 of e.xtinct mammals in the British Museum. Alone of 

 European pateontologists, he has likewise visited the 

 rich collections recently amassed in the museums of 

 Buenos .Ayres and La Plata. He has thus the advantage, 

 not possessed by any previous writer on the subject, of 

 a more intimate acquaintance with the past history of 

 mammals than perhaps any other living naturalist has 

 been able to accumulate, and on the present occasion has 

 made good use of it. 



In the main outlines of his scheme of geographical 

 regions, as propounded in the introductory chapter of the 

 present work, Mr. Lydekker follows generally the well- 

 known arrangement of Sclater and Wallace ; but, as we 

 shall presently show, deviates from their views in several 

 important particulars. As to the correctness of the 

 primary division of the earth's surface into " Notogsa," 

 " Xeog;ca," and " Arctogjea," all authorities, we believe, 

 whose opinions are worthy of consideration, are now 

 nearly in accord. This arrangement was first proposed 

 by Mr. Sclater in 1858, in one of the " Manchester 

 Science Lectures," though other titles were then given to 

 the two last-named divisions. In 1890, Dr. Blanford 

 adopted the same prmiary areas with slight alterations 

 in the names. The "anonymous writer" in Natural 

 Science, \i\io,\x\ 1893, assigned the names "Notogasa," 

 " Neog?ea," and " Arctog;ea " to these three divisions, 

 we take to have been Mr. Sclater himself, or some one 

 inspired by him. At any rate, these are the terms 

 adopted by Mr. W. L. Sclater in his articles on the 

 " Geography of Mammals," lately published in the 

 Geoi^raphical Journal ; and we agree with Mr. Lydekker 

 in regarding them as the simplest and best-selected 

 names yet proposed. But, having proceeded thus far, we 

 have only arrived at the front of our difficulties. 



".\rctogiea" embracing the whole land-surface of the 

 world e.xcept Australia {Noiogcca), and South and Central 

 America {Neogcea), requires subdivision. Messrs. Sclater 

 and Wallace have proposed to effect this in the most 

 simple and natural way, by making four " regions " out of 

 " Arctog;ea " — namely, the Ethiopian, Oriental, Pakv- 

 arctic and Nearctic, and thus to recognise six primary 

 zoological regions. They admit, of course, that these six 

 regions are not of exactly equal value. But in such a 

 matter, as in all other classifications, convenience should 

 be consulted to a certain extent, and the "six regions" 

 are very convenient, being readily defined and easily 

 recognisable, and are much more in accordance with facts 

 NO. 1403, VOL. 54J 



II. Neogsic realm 

 III. Arctogoeic realm 



than any other regions that have yet been suggested. 

 Mr. Wallace has set all this fully forth in an address to 

 the Cambridge Philosophical Society, which was published 

 in this journal in April 1894.' We regret to observe that 

 Mr. Lydekker scoffs at this excellent and well-reasoned 

 article, and speaks of it as an attempt to "bolster up" a 

 lost cause. Yet he continually refers to Mr. Wallace's 

 writings throughout his work, and acknowledges his 

 eminence as an authority on geographical distribution. 



Mr. Lydekker summarises his objections to the " six 

 regions " of Sclater and Wallace as follows ; — 



" It has the serious drawback that it gives no greater 

 rank to Australasia and South America than to the other 

 divisions ; whilst the remarkable difference' between the 

 faunas of Africa and Madagascar is overlooked. Further, 

 the northern parts of America are widely separated from 

 those of Europe and Asia, to which they are faunistically 

 allied." 



Mr. Lydekker proposes the following modified scheme 

 to meet the defects thus specified. 



I. Notogxic realm (l) Australian region. 



(2) Polynesian region. 



(3) Hawaian region. 



(4) Austro-Malayan region. 

 Neotropical region. 



(1) Malagasy region. 



(2) Ethiopian region. 



(3) Oriental region. 



(4) Holarctic region. 



(5) Sonoran region. 



We venture to assert that these suggested modifications 

 only lead Mr. Lydekker into further difficulties. 



In the first place, realm is only region " writ short," 

 and is hardly sufficiently distinct to be used in a different 

 sense. Why not say simply " Notogsa," " Neogsea," 

 and "Arctogrea"— three orthographically constructed 

 compounds, of which the meaning is patent to all ac- 

 quainted with the subject ? Again, the so-called 

 " Polynesian region " is a mere appendage of the Austra- 

 lian region. As Mr. Lydekker well says, it is " character- 

 ised by the general absence of non-flying inammals." 

 But the birds — the next important group — are mostly 

 Australian in character, though a few genera are autoch- 

 thonous. The Moas {Dinornithida) which, until lately, 

 played such an important role in it, are certainly as nearly 

 related to the Cassowaries as to any other group. Lories 

 (a specially characteristic Australian type) are scattered 

 over it. In fact, Polynesia can only be properly placed 

 as one of the sub-regions of the Australian region. 



Much the same may be said of Mr. Lydekker's 

 " Hawaian region." The only mammal of the Sandwich 

 Islands is a bat. The land-birds are certainly very 

 peculiar, and mostly restricted to the group. It is, as yet, 

 not ascertained to what outside forms they are most 

 nearly related ; it is quite certain, however, they have 

 nothing to do with America. But to rank the Hawaian 

 Islands as constituting a division equal in value to the 

 Ethiopian region is simply impossible. The alleged 

 inequality of Sclater and Wallace's six regions is a trifle 

 compared with this feat of Mr. Lydekker. The best place 

 for the so-called " Hawaian region," so far as our 

 present knowledge goes, is within the boundaries of the 

 Australian. 



1 See '■ What are Zoological Regions?" (N.MURE, vo'. .\'i.-.. p. 6ii). 



X 



