i BIOLOGY, PHYSICS AND CHEMISTRY 37 



life (excepting, of course, assimilation, growth, and 

 reproduction) is of the katagenetic order, exhibiting 

 the fall, not the rise, of energy. It is only with these 

 facts of katagenetic order that physico-chemistry deals 

 that is, in short, with the dead and not with the living. 1 

 The other kind of facts certainly seem to defy 

 physico-chemical analysis, even if they are not anagenetic 

 in the proper sense of the word. As for the artificial 

 imitation of the outward appearance of protoplasm, 

 should a real theoretic importance be attached to this 

 when the question of the physical framework of 

 protoplasm is not yet settled ? We are still further 

 from compounding protoplasm chemically. Finally, a 

 physico-chemical explanation of the motions of the 

 amoeba, and a fortiori of the behaviour of the In 

 fusoria, seems impossible to many of those whc 

 have closely observed these rudimentary organisms. 

 Even in these humblest manifestations of life they 

 discover traces of an effective psychological activity. 2 

 But instructive above all is the fact that the tendency 

 to explain everything by physics and chemistry is 

 discouraged rather than strengthened by deep study of 

 histological phenomena. Such is the conclusion of the 

 truly admirable book which the histologist E. B. 

 Wilson has devoted to the development of the cell : 

 &quot;The study of the cell has, on the whole, seemed to 



1 Cope, The Primary Factors of Organic Evolution, Chicago, 1896, pp. 

 4.75-484. 



2 Maupas, &quot; Etude des infusoires cilies &quot; (Arch, de zoologie exptrimentale, 

 1883, pp. 47, 491, 518, 549, in particular). P. Vignon, Recherches de 

 cytologie g/ne rale sur les epitheliums, Paris, 1902, p. 655. A profound study 

 of the motions of the Infusoria and a very penetrating criticism of the 

 idea of tropism have been made recently by Jennings (Contributions to the 

 Study of the Behaviour of Lower Organisms, Washington, 1904). The 

 &quot; type of behaviour &quot; of these lower organisms, as Jennings defines it 

 (pp. 237-252), is unquestionably of the psychological order. 



