482 



NATURE 



[April 20, 1876 



follows : — At the present time glaciers enter the sea, within 

 the northern hemisphere, down to the latitude of 60° ; the 

 sea is frozen and ice-marks are produced on the shore as 

 far south as 40° ; and icebergs drop their rocky burdens 

 within :i7° degrees of the equator. If there ever prevailed 

 a universal glacial period with a general reduction in the 

 temperature of the whole northern hemisphere, we ought 

 to find traces of glacial action everywhere round the 

 whole globe and extending even to more southern lati- 

 tudes than 37°. If the ice- cap " ever existed, the marks of 

 it ought to be found on all meridians alike. If ever there 

 was a glacial period in our world, glacial marks ought to 

 be found everywhere, in the same latitudes and at the 

 same levels, in the same state of preservation." 



Keeping these premises constantly before his mind, our 

 author found, during his journey of eleven months, quite 

 sufficient evidence to cause him to make a full retraction 

 of his former conclusions on the subject. As far as 

 Chicago he observed everywhere the most striking 

 traces of former glacial action ; but in the same latitudes 

 to the westward he found these marks of old glaciers 

 entirely disappearing ; and although some signs of glacial 

 action were detected in the Rocky Mountains themselves, 

 yet from this great range onwards to Ceylon they were 

 found to be wholly wanting. Mr. Campbell's previous 

 expedition in eastern Europe had led him to conclusions 

 as to the local character of glacial action which were quite 

 in harmony with those obtained in this journey round 

 the globe, and he enunciates the results of his latest obser- 

 vations upon the subject as follows : — " Whether I take 

 marks which can be explained by glacial erosion, such as 

 firths, valleys, lakes, &c., or marks which clearly are not 

 glacial, such as peaks and canons, I find nothing to suggest 

 a general glacial period in America or in Europe ;" and 

 he further proceeds to state that he can find no evidence 

 whatever of a recurrence of universal glacial periods such 

 as might result from the action of some astronomical 

 cause. 



We have already extended this notice of Mr. Camp- 

 bell's valuable work to the farthest limits, and must refer 

 to the book itself for the details of the evidence on which 

 his conclusions are founded. 



In bringing our remarks to a close, we may add 

 that the author's present views on the influence pro- 

 duced on climate by the changes of level in different 

 districts, resulting in alterations in the direction of 

 ocean currents, &c., appear to be quite in harmony 

 with those so long and firmly maintained by Lyell, in 

 opposition to the cosmical theories of the extreme 

 glacialists. His observations on Western North America 

 are fully confirmed by the more detailed examination of 

 the districts by several of the United States' geologists ; 

 and his conclusion that there is no evidence of the former 

 existence of a general " Glacial period " are quite in 

 accordance with those enunciated by Dr. Hector and 

 other observers who have studied the glaciers of the 

 southern hemisphere. Prof. Nordenskjold has, moreover, 

 shown how completely palcEontological evidence of the 

 clearest character disposes of the notion of frequently 

 recurring glacial epochs in past geological times. 



We cannot but admire the candour with which Mr. 

 Campbell renounces his previously-expressed opinions ; 

 and we may, perhaps, be allowed to express a hope that 



the facts and arguments which have led him to so greatly 

 modify his views on glacial phenomena, will not be with- 

 out effect on the minds of others, who, like him, have 

 certainly pushed their conclusions derived from a study 

 of very limited portions of the earth's surface, to generalis- 

 ations far beyond what those observations can be legiti- 

 mately made to support. J. W. J. 



SCLATER'S "GEOGRAPHICAL ZOOLOGY" 

 On the Present State of our Knowledge of Geographical 

 Zoology. By P. L, Sclater, M.A., F.R.S. Being the 

 Presidential Address delivered to the Biological Section 

 of the British Association. (London, Printed by Taylor 

 and Francis : 1875.) 

 "IT rE have received a copy of Mr. Sclater's ad- 

 V V dress as President of the Biological Section 

 of the British Association, at its meeting last year, 

 at Bristol, At the time when it was delivered we 

 had the opportunity of presenting it in full to our 

 readers {vide Nature, vol. xii. p. 374, et. seq.). In the in- 

 dependent form now under notice it has added to it a 

 most important appendix, namely, a list of all the works 

 and memoirs referred to in its various sections. When 

 we say that these are more than 420 in number, a fair 

 estimate may be formed of the labour which must have 

 been involved in their collection and classification. Exact 

 references are a most valuable aid to biological research, 

 and prevent the waste of much time during special in- 

 vestigations, and on the subject of the geographical distri- 

 bution of vertebrated animals, this address of Mr. Sclater's 

 supplies all that can be wanted by anyone either reviewing 

 the subject as a whole, or desiring to obtain the best 

 information on the zoology of any special locality. 



The arrangement adopted is regional, the basis being 

 the universally accepted divisions proposed by Mr. 

 Sclater himself. They are thus tabulated : — 



I 



\ Arclogaea, 



Dendrogaea. 



Antardogaea. 

 Ornithogaea. 



I. — Paloearctic Region . 

 II. — Ethiopian Region 



\\a. — Lemurian Sub-region 



III. — Indian Region 



IV. — Nearctic Region . . 

 V. — Neotropical Region . 



Va. — Antillean Region 



VI. — Australian Region . 

 VII. — Pacific Region 

 Each of these regions is divided into sub-regions, 

 which are described separately. Perhaps no better idea 

 can be formed of the extent to which the greater divi- 

 sions of the globe have been studied, than by a com- 

 parison of the number of works and memoirs which 

 have appeared with reference to each, or to parts of each. 

 As might be premised, there has been much written on 

 the animals of the Palaearctic region, considering that it 

 includes Europe, together with North Africa, Siberia, and 

 North China. There are 119 references with regard to it, 

 the most recent including Prof Lilljeborg's work on the 

 Mammals of Sweden and Norway, Mr. Dresser's " Birds 

 of Europe," Mr. J. Hancock's " Birds of Northumberland 

 and Durham," Dr. Schreiber's " Herpetologia Europaea," 

 the German translation of Dr. N. Severzow's work on the 

 Birds of Turkestan, the late Dr. Stoliczka's "Avifauna of 

 Kashgar in Winter," Lieut.-Colonel Irby's " Ornithology 

 of the Straits of Gibraltar, ' and the new edition of Bell's 

 " British Quadrupeds." 



