THEORIES OF INDIVIDUALITY 25 



These hypotheses are open to various objections. 

 The crystal consists primarily of like molecules though 

 under certain conditions some crystals may show differ- 

 ences in constitution at the two poles resulting from the 

 presence of other substances besides the primary con- 

 stituent of the crystal. The organism, on the other 

 hand, is a complex of many different kinds of molecules, 

 some of which are undergoing breakdown and being 

 built up anew during life, and, moreover, there is no 

 optical or other evidence that protoplasm in general is 

 fundamentally crystalline in structure. The unity of 

 the crystal is a static unity, a unity of form and arrange- 

 ment, and disappears or is replaced by another unity 

 when chemical change occurs, while the unity of the 

 organic individual is a dynamic unity dependent pri- 

 marily for its existence on chemical activity and dis- 

 appearing when such activity ceases. To believe that 

 metabolism results from structure and "organization" 

 as the activity of the man-made machine results from 

 its structure is to ignore the fact that metabolism is the 

 formative agent in the organism. Undoubtedly crystals 

 or crystalloid individuals are present in at least many 

 organisms, but their individuality is quite distinct from 

 that of the organism. 



Some biologists, while not admitting that the organ- 

 ism is fundamentally crystalline, assume that its con- 

 stituent molecules possess unknown properties which 

 determine its unity and order. These hypotheses are 

 open to the same objections as the crystal hypotheses. 

 All such hypotheses in fact proceed on the assumption 

 that a certain more or less complex " organization " 

 is necessary as a starting-point; the machine must 



