158 The In s/i Naturalist. September, 



centro tlirough wliicli definite variations are worked ont, the antithesis of 

 nutrition an 1 reproduction — as might be expected from former specu- 

 lations of theirs — taking a prominent place. On this view of the 

 evolutionary process, "the importance we have been taught by Darwin 

 to assign to natural selection becomes greatly changed — from selecting and 

 accumulating supposed intleflnite variations, to that mainly of retarding 

 definite ones, after their maximum utility has been independently reached 

 . it furnishes the brake rather than the steam or the rails for the 

 journey of life." It is perhaps likely that future research will justify our 

 authors' belief in the importance of " definite variations." As things are, 

 it is well that such speculations should not be " dogmatically pressed." 



G. H. C. 



AN INTRODUCTION TO ZOOLOGY. 



The Animal World. By F. W. Gamble, F.R.S., with Introduction ])v 

 b}- Sir Oliver Lodge, F.R.S. Pp. 256. London : Williams and Norgate 

 (Home University Library of Modern Knowledge). Price 15. net. 



In this brightly -written volume the reader will find an excellent intro- 

 duction to the study of animal life. Prof. Gamble's book is not a condensed 

 zoological text-book of the ordinary kind, but comprises a series of vivid 

 sketches of various aspects from which animals may be regarded. Opening 

 with a chapter on structure and classification, he gives us successively 

 accounts of Animal Movements and Distribution, the (juest for Food, 

 Breathing, Colour, Senses, Societies, the Care for Young, Life-Histories, 

 and finally Heredity and X'ariation. It may perhaps be doubted if the first 

 chapter is well adapted to lead a beginner into zoological paths. To 

 introduce at once the unfamiliar Protozoa, and then the groups of the 

 animal kingdom set forth in terms of the germ -layer and coeloni theories, 

 runs counter to the sound educational })ractice of leading the learner from 

 the known to the unknown. Nevertheless this first chapter is a masterly 

 piece of summarised writing. 



The subsequent chapters, treated from the physiological or the bionomic 

 standpoint, are thoroughly attractive and inspiring ; nothing more likely 

 to arouse interest in animal life can be imagined. Old and familiar 

 facts may here be found in a new setting, combined with many recent 

 discoveries, and the reader cannot fail to realise that zoology, truly con- 

 ceived, is a study of life and function. Among the few inevitable slips it 

 may be pointed out that the rostrum or modified second maxilla; of the 

 Hcmiptera is not a lancet-like instrument or a piercing hollow spine (p. 82), 

 but the sheath in which the actual piercers — mandibles and first maxilla; — 

 work to and fro. The book is illustrated by a number of useful but roughly 

 executed drawings. 



G. H. C. 



