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SOME NEW BOOKS. 



The Whole History of Fishes. 



Fishes, Living and Fossil : An Outline of their Forms and Probable 

 Relationships. By Bashford Dean, Ph.D. Pp. xiv., 300, with 344 woodcuts 

 and frontispiece. New York and London : Macmillan & Co., Ltd., 1895. Price 

 IDS. 6d. nett. 



For the first time in the history of Ichthyology, students are now 

 provided with an elementary handbook affording a general view of 

 the whole subject. This has not come to displace the still-invaluable 

 " Introduction to the Study of Fishes," published by Dr. Giinther 

 nearly sixteen years ago. The latter aims chiefly at a systematic 

 survey of the fishes existing at the present day, with only casual 

 references to their ancestry. The new work for elementary students 

 by Dr. Bashford Dean, of Columbia College, New York, deals rather 

 with the fundamental problems of morphology than with the present- 

 day aspect and distribution of fishes, and, as such, takes a distinct 

 place. The time-honoured perch is deposed from his usual position 

 as the fish of all fishes — the standard for comparison with other types 

 of the class. Dr. Dean's view of piscine morphology is much more 

 general, and in conformity with modern research. To describe the 

 skeleton of a perch as that of a typical fish is about as misleading as 

 would be the description of the household of a prince or a millionaire 

 as typical of the ordinary establishment of a civilised man. Dr. Dean 

 recognises this fact and arranges his elementary treatise accordingly. 

 The brief introductory chapter deals in a novel manner with the 

 adaptation of fishes to life in a watery medium, and then recapitulates 

 a few of the principal results of ijiodern research in reference to their 

 evolution, distribution in time, and classification. The Class Pisces 

 (true fishes with paired limbs and a lower jaw) is divided into the four 

 sub-classes of Elasmobranchii, Holocephali, Dipnoi, and Teleostomi ; 

 the last again subdivided into the orders Crossopterygii and Actino- 

 pterygii. The table showing " The Distribution of Fishes in Geological 

 Time" is based chiefly upon Zittel's " Handbuch," and needs much 

 revision. More details as to the evolution of structures characteristic 

 of fishes are added in chapter ii., which occupies over forty pages ; 

 and these observations are illustrated by numerous instructive 

 diagrams relating to the gills, air-bladder, dermal defences, teeth, 

 fins, and the sense-organs of the lateral line. Most of the exposition 

 will be admitted by all morphologists, and so far as it goes it is very 

 clear ; but there is scope for considerable difterence of opinion with 

 reference to the section on fins, which is based partly upon the 

 author's own researches, and very largely on those of Thacher, 

 Balfour, Mivart, Dohrn, and Wiedersheim. The concluding remarks 

 on the " pineal eye " are particularly interesting ; for Dr. Dean 

 himself has devoted much attention to the subject, and he remarks 



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