22 INDIVIDUALITY IN ORGANISMS 



the importance of this fundamental point. There has 

 been much discussion of "formative substances" and 

 their distribution and role, and the magic word "organi- 

 zation" has served as the all-sufficient answer to many 

 questions, while the fundamental problem of unity and 

 order involved in the origin and action of the so-called 

 formative substances and in the nature of organization 

 has too often been completely neglected. 



Various theories of the organism, which may be called 

 corpuscular theories, have been advanced and have met 

 with more or less general acceptance. Among these 

 Weismann's germ-plasm hypothesis is most familiar and 

 has played the most important role in biological thought. 

 These theories postulate in one form or another a multi- 

 tude of specific material entities, each of which represents 

 in some way some characteristic of the organism. The 

 organism as we know it is the product of their combined 

 and harmonious activity. Examination of these theories 

 shows that these hypothetical entities, gemmules, 

 determinants, physiological units, pangenes, specific 

 accumulators, or whatever we prefer to call them, are 

 themselves endowed, ex hypothesi, with the essential 

 characteristics of individuals and that the organism as 

 a whole is merely a composite of their orderly activities. 

 Neither the problem of the individuality of the hypo- 

 thetical units nor that of their orderly combination and 

 unification in the organism receives any adequate con- 

 sideration in those theories. They merely translate 

 the problem into hypothetical terms which are beyond 

 the reach of scientific method. The combination of 

 these units into the individual is assumed to occur as the 

 facts demand, and although the problem of the control 



