CONCLUSIONS AND SUGGESTIONS 201 



If we accept this view, we must regard gametic 

 reproduction merely as a more highly spcciaHzed form 

 of reproduction which occurs in more advanced life 

 or in more highly differentiated individuals than agamic 

 reproduction, but which involves essentially the same 

 cycle of differentiation and senescence, followed by 

 dedifferentiation and rejuvenescence, the production of a 

 new individual, and another period of differentiation 

 and senescence. 



From this standpoint the egg and the embryo are 

 in general the most unfavorable material that could be 

 found for the investigation and analysis of the processes 

 of reproduction and individuation, for in most cases the 

 gametes are formed in the parent organism under C(jn- 

 ditions which do not permit of extensive and exact ex- 

 perimental control. Moreover, they consist of single 

 cells, and so cannot be divided experimentally before de- 

 velopment begins, and the egg has usually attained a 

 certain, often a very high, degree of individuation before 

 it is isolated. The agamic and experimental reproduc- 

 tions afford a much wider range of control, and we can 

 analyze the beginnings of individuation there as we can- 

 not in the egg. The only logical procedure is, in my 

 opinion, to interpret gametic reproduction, as 1 have 

 attempted to do, on the basis of our knowlerlge of the 

 experimental and agamic processes, and not vice versa. 

 Our slow progress toward an adequate conception of 

 organic individuality has undoubtedly been due in con- 

 siderable part to the fact that we have confined our 

 attentioTi so largely to gametic reproduction, and have 

 neglected the simpler processes in which, if anywhere, 

 the key to the problem is to be found. 



