ROUX : FORM AND FUNCTION 329 



and independent of functioning; it implies a living and 

 co-ordinated activity of the tissues and organs concerned, 

 a power of active response to foreseen and unforeseen 

 contingencies. Form is then not something fixed and 

 congealed it is the ever-changing manifestation of 

 functional activity. " Since most of the structure and form 

 of the blood-vessels arises in direct adaptation to function, 

 the vessels of adult men and animals are no fixed structures, 

 which, once formed, retain their form and structural build 

 unchanged throughout life ; on the contrary, they require 

 even for their continued existence the stimulus of functional 

 activity. . . . The fully formed blood-vessels are no static 

 structures, such as they appear to be according to the 

 teaching of normal histology, and such as they have long 

 been taken to be. Observation and description of normal 

 development never shows us anything but the visible side 

 of organic happenings, the products of activity, and leaves 

 us ignorant of the real processes of form-development and 

 form-conservation, and of their causes" (p. 125, 1910). 



The real thing in organisation is not form but activity. 

 It is in this return to the Cuvierian or functional attitude 

 to the problems of form that we hold Roux's greatest 

 service to biology to consist. The attitude, however, seems 

 to smack of vitalism, and Roux, as we have seen, is no 

 vitalist. He holds that the marvellous and apparently 

 purposive tissue-qualities which underlie all processes of 

 functional adaptation have arisen " naturally," in the course of 

 evolution, by the action of natural selection upon the various 

 properties, useful and useless, which appeared fortuitously 

 in the primary living organisms. He is, moreover, deeply 

 imbued with the materialistic philosophy of his youth, and it 

 is indeed one of the chief characteristics of his system that he 

 states the fundamental properties or qualities of life in 

 terms of metabolism. A vital quality is for Roux a special 

 processor mode of assimilation. The faculty of "morpho- 

 logical assimilation " whereby form is imposed upon formless 

 chemical processes is the ultimate term of Roux's analysis 

 " the most general, most essential, and most characteristic 

 formative activity of life" (p. 631, 1902). 



We have now to consider very briefly the early results 



