24 THE SCOTTISH NATURALIST 



BOOK NOTICE 



The Philosophy of Zoology. By James Johnstone, D.Sc, pp. xv. 

 and 391. Cambridge, at the University Press, 1914- Qs. net. 



The science of zoology to most observers is a medley of innumer- 

 able and more or less isolated facts. Endeavours to weld this chaos of 

 information into a unified system of knowledge have given rise to the 

 speculations, theories, and hypotheses which constitute the Philosophy of 

 Zoology and the subject-matter of this volume. Dr Johnstone, however, 

 confines his attention mainly to an examination of the phenomena of 

 living things as bearing upon the question of the ultimate nature of life. 

 In regard to this problem the solutions of philosophy have periodically 

 fluctuated between the extremes of a purely naturalistic or mechanistic 

 explanation and that of a spiritual or vitalistic interpretation. With the 

 teaching of Bergson and Driesch at the present moment the pendulum 

 has swung from the frank materialism of Huxley to a " vitalism" which 

 more than ever bases its claims on a minute sifting of biological fact 

 gained from experience and experiment. The present volume belongs 

 to the latter school, and, although it lacks the grip of Driesch and the 

 fluency of Bergson, it presents with fairness and circumstantial detail 

 the present position of the vitalistic school. The difficulties and 

 impossibilities of a physico-chemical concept of life are shown up by minute 

 dissection of the claims and suppositions involved ; and the presence of 

 a power apparently different from the energies of physics and chemistry 

 is made wonderfully clear. It is impossible to trace the complexities 

 of the argument, but evidences for the existence of this power, " entelechy," 

 "vital impulse," or whatever it may be called, which directs and controls 

 the manifestations of life, are drawn from examination of the mechanical 

 and vital activities of living things, from the purposeful and co-ordinated 

 variation of individuals, and from the definite trends of evolution. A 

 few misprints and minor errors catch the eye, as on p. 84, 1. 7 from 

 bottom ; p. 146, 1. 24, "reserved" should be reversed j the second sentence 

 dealing with the ridges on a cockle-shell on p. 187 is far from clear; 

 there is an unattached footnote on p. 224 ; and on p. 276, 1. 4, " Verte- 

 brate" should read Arthropod. 



In his survey, Dr Johnstone gathers facts from wide fields, and the 

 result is a comprehensive critical study which will be of value not only 

 to the vitalist and the mechanist, but to the general student who cares 

 to grasp the deeper significance of life and its manifestations. — J. R. 



