234 SENESCENCE AND REJUVENESCENCE 



Such reproduction is possible only where the isolated part is capable 

 of reacting to the isolation by dedifferentiation and reconstitution. 

 According to this conception, agamic reproduction in organisms 

 results in one way or another from the physiological or physical iso- 

 lation of a subordinate part from the influence of the dominant part. 

 At first glance gametic or sexual reproduction appears to be a totally 

 different kind of reproduction, but, except for the occurrence of 

 fertilization, it is in reahty very similar to the agamic process. 

 Before taking up the problem of sexual reproduction, however, it is 

 necessary to consider the relation between individuation, agamic 

 reproduction, and the age cycle. 



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