NOTICES OF NEW BOOKS. ' 43 



connection between the Mediterranean and Japanese Seas are 

 supported by Dr. Alcock, who considers that the " hypothesis 

 that appears to offer the most satisfactory explanation is, that a 

 very considerable part of the fish fauna of the Oriental region 

 originated from, and to a certain extent is a remnant of, the fauna 

 of the Tertiary Mediterranean of Prof. Suess — of a Mediterrnean 

 that extended from the present Gulf of Mexico, through the 

 present Mediterranean basin, far into the Eastern Hemisphere." 

 Species whose distribution may be used as evidence for this 

 hypothesis are not only pointed out among these fishes, but also 

 have been detailed by Dr. Alcock among the deep-sea Madre- 

 poraria and Brachyura of the same region. If the number of 

 Indian genera of marine fishes are estimated at three hundred 

 and fifty, and of species at one thousand two hundred ; " then 

 over fifty-six per cent, of the genera and close on five per cent, 

 of the species are also found in the Atlantic-Mediterranean 

 region." The argument is much advanced and clearly elucidated 

 by a large chart compiled from Plate 11 of Dr. E. Koken's 'Die 

 Vorwelt und ihre Entwickelungsgeschichte,' showing the supposed 

 coast-lines of the Tertiary continents and the then Great Inland 

 Sea. 



The Rainbow Trout. By Charles Edward Walker and Charles 

 S. Patterson. Lawrence & Bullen, Limited. 

 The Rainbow Trout (Salmo irideus var. Shasta), whose natural 

 home is the Pacific slope rivers, has been largely introduced into 

 the waters of various portions of the world. It has succeeded 

 wonderfully well in New Zealand, where specimens have been 

 taken reaching nine pounds in weight ; in this country one of 

 the first authentic reports of its colonization was a capture in 

 Warwickshire in 1892 from a lake stocked in 1890. But success 

 in the introduction of this fish depends upon a proper knowledge 

 of its life-history. " The natural zone of the Rainbow Trout 

 may be roughly said to be from 35° to 45° N. — that is to say, the 

 latitude of Spain and the South of France " ; and the best 

 developed form of the true S. irideus var. Shasta " has for its 

 original environment water not liable to freeze, and situated in a 

 country the mean temperature of which is not below 55° F., and 



