66o LIFE : OUTLINES OF GENERAL BIOLOGY 



since there enter into it the future under the form of prospectivt- 

 tendency or horme, and the past under the form of retrospective 

 bias or mneme ; while the present too is regulated through elementary 

 perception. And since responses involve the orderly activities of 

 many organs, and thus of their many component cells, they corre- 

 spond to the functions of ordinary physiological language, save 

 that we must now ascribe to these the same elementary psychical 

 moments — awareness, mnemic action, and regulability — which 

 characterise the responses of the organism as a whole. A cell's or 

 organ's function is thus not the materially determined outcome of the 

 physico-chemical configuration, as for the materialistic philosophy; 

 it is an activity sui generis of the living unity, and not completely 

 reducible to physico-chemical processes, though dependent upon 

 these. The analytic scope for physico-chemical research is next 

 outlined; but the general functionings and responses are reserved 

 to biology proper. The metabolic functions— of feeding, digestion, 

 absorption, transport of material, storage, secretion, excretion, and 

 respiration -render possible that of differential growth, fundamental 

 to development and differentiation (or de -differentiation), which 

 may be taken with multiplication by division and regeneration of 

 lost parts. Apart from these morphogenetic functions, movement 

 and receptivity are next considered. 



Keeping as far as may be the term functions for activities of the 

 parts, and responses for activities of the whole, these latter are 

 grouped as self-maintenance, development, and reproduction, the 

 fundamental hormic impulses of life, which are again expressed in 

 terms beyond those of the simply physico-chemical level of explana- 

 tion. Yet this functional method requires no recourse to any proble- 

 matical interaction of the physical and the psychical (if such exist 

 separately, save as logical blind alleys or termini of thought). It 

 deals with the living being as a psycho-physical unity, before 

 dissociation into its two complementary aspects. In his final chapter, 

 the outlook for this functional biology, Dr. Russell indicates lines 

 of attack on major problems. He repeats the rejection of the 

 hypothesis of material determinism, and reaffirms limitation of bio- 

 physics and biochemistry to adjuncts of biology proper, and especi- 

 ally with regard to the material conditions of life and associated 

 functioning in detail. He reserves for functional biology proper the 

 study of vital phenomena in terms of functions and responses, with 

 constant regard to the prospective and retrospective character of 

 these activities, and in particular to the all-important fact of 

 regulation. As examples of how this will work out in practice, he 

 takes the main problems and theories of development and heredity; 

 and criticises their long predominant insistence on the material 

 aspects of the process. Stating them in terms of the functional 

 activities, present in the fertilised ovum from the outset, there is 



