May 17, 19 1 7] 



NATURE 



22 



is evidently intended mainly for the author's 

 countrymen, to whom an acquaintance with the 

 fresh-water fishes is of considerable practical use, 

 for the Russian fresh-water fisheries are very valu- 

 able. The true fresh-water fishes, indeed, are not 

 ■of much account, but the migratory fishes, such 

 as the salmon (quinnat, humpback, etc.) of the 

 North Pacific, the char (Salvelinus) and whitefish 

 (Coreg-onus) of the Arctic Ocean, the sturgeons, 

 trout (Sahno labrax), and shad (Caspialosa) of the 

 Black and Caspian Seas, are of great economic 

 importance. The value of these anadromous 

 fishes is due to two causes : first, they draw their 

 food supply from the abundance of the sea and so 

 are superior in size and numbers to the permanent 

 inhabitants of the rivers, and, secondly, they con- 

 x:entrate at certain seasons to ascend the rivers to 

 their breeding-grounds, when their capture in 

 large quantities is easy enough. 



An introductory chapter deals with structure 

 and classification ; this is up to date, and recent 

 research on the morphology of the teleostean fishes 

 is appreciated. In the systematic part of the 

 work 281 species and about 100 sub-species are 

 described, and the majority of them are figured ; 

 this is followed by a table illustrating in detail 

 their geographical distribution, whilst a final 

 chapter deals with the Palcearctic region and its 

 division into sub-regions and provinces. 



Prof. Berg recognises six sul>regions, Medi- 

 terranean, Arctic, Baikal, central Asiatic, Man- 

 churian, and Chinese. In this classification con- 

 siderable importance is attached to the ana- 

 dromous fishes, and if these be neglected, and 

 only the true fresh-water fishes, the bulk of which 

 are Cyprinoids, be considered, a somewhat dif- 

 ferent result may be arrived at. The first three 

 divisions might then be united to form a single 

 sub-region, comprising Europe, with northern and 

 western Asia; the fourth, the mountain region of 

 central Asia, would stand ; and the fifth and sixth 

 might be added together to make an eastern sub- 

 region, including the greater part of China, with 

 Manchuria, Corea, and Japan. In each of the 

 three areas just delimited the majority of the 

 Cyprinoid genera and species are endemic. 



The Manchurian (or Amurian) sub-region is 

 established as transitional between the Arctic and 

 Chinese sub-regions. A certain number of 

 Siberian fishes occur in the Amur, but Chinese 

 types are more numerous. The migratory Sal- 

 monidae of the Okhotsk Sea also help to charac- 

 terise this division. An interesting example of 

 discontinuous distribution is the presence in the 

 Vmur of the European bitterling^ [Rhodeus 

 sericeus), which is not found elsewhere east of the 

 Volga. 



Prof. Berg's Arctic and Mediterranean sub- 

 regions are distinguished by the absence 

 of certain Cyprinoids from the former, but 

 chiefly by the difference between the ana- 

 dromous fishes of the Arctic Ocean and 

 those of the Black and Caspian Seas. This 

 difference is of considerable interest in its 

 bearing on the theory that the Caspian Sea was 

 directly connected with the Arctic Ocean in com- 

 NO. 2481, VOL. 99] 



paratively recent times. The fish fauna of the 

 Black Sea has two principal components : (i) an 

 old Sarmatian fauna, also represented in the Cas- 

 pian, and (2) recent immigrants from the Medi- 

 terranean, unrepresented in the Caspian. Simi- 

 larly, the Caspian fishes have a double origin, 

 including (i) genera or species that are peculiar 

 to the Black and Caspian Seas, and {2) fresh-water 

 species that have entered it from its tributaries and 

 that live in those areas where the salinity is sufl5- 

 ciently low. The fishes give no support to the 

 theory of a recent Arctic-Caspian connection, and 

 there does not appear to be any definite geological 

 evidence in its favour. 



Lake Baikal has most of the true fresh-water 

 fishes of the Yenisei, including a number of our 

 most familiar British species, roach, dace, min- 

 now, pike, perch, etc. ; »it also has a char and 

 two Coregoni, relict forms of anadromous Arctic 

 species; but the Baikal fish fauna is characterised 

 by the presence of nearly a score of Cottidae, 

 which have found the vast area and great depths 

 of the lake favourable to their evolution and have 

 even given rise to a genus, Comephorus, which is 

 generally regarded as the type of a distinct 

 family. These Baikal Cottids seem to have come 

 from an older and more primitive stock than the 

 other Palaearctic species of the family, and they 

 bear witness to the antiquity of the lake; but 

 there is no evidence that they were directly of 

 marine origin. 



We are grateful to Prof. Berg for this fine 

 volume; in its preparation he has studied a very 

 complete material, comprising series of specimens 

 from every_ lake and river in the Russian Empire, 

 and the result is a work that is authoritative and 

 of permanent value. C. T. R. 



CHEMISTRY BOOKS FOR SCHOOL AND 

 LABORATORY. 



(i) Text-book of Elementary Chemistry. By 

 Dr. F. Mollwo Perkin and Eleanor M. Jaggers. 

 Pp. vii+384. (London: Constable and Co., 

 Ltd., 1916.) Price 35. net. 



(2) Elementary Practical Chemistry. Part ii. 

 By Prof. F. Clowes and J. Bernard Coleman. 

 Eighth edition. Pp. xvi + 255. (London: 

 J. and A, Churchill, 1916.) Price 35. 6d. net. 



(3) Technical Chemists' Handbook. Tables and 

 Methods of Analysis for Manufacturers of 

 Inorganic Chemical Products. B'v Dr. George 

 Lunge. Second edition, revised. Pp. xvi + 264. 

 (London : Gurney and Jackson, 1916.) Price 

 I05. 6d. net. 



(4) Chemistry for Rural Schoots. By E. Jones 

 and A. Jones Griffith. Pp. 184. (London : 

 Blackie and Son, Ltd., 1916.) Price 2s. 6d. 

 net. 



(5) A Text-hook of Quantitative Chemical 

 Analysis. By Drs. A. C. Gumming and S. A. 

 Kay. Second edition. Pp. xv + 402. (London: 

 Gurney and Jackson, 191.6.) Price 95. net. 



(i) A LMOST at the beginning of this little 



^^ volume the student is directed to make 



an experiment, whereby he may find out for him- 



