Reduction 5 1 



the centrosome of an earlier division retained 

 by the tension of the envelope. If there were 

 no envelope, the separation of the polar body 

 from the reorganized cell would quickly take 

 place and the new cell would have all the 

 characters of the old, and its general or un- 

 specialized powers. But where growth domi- 

 nates over reproduction, the envelope receives 

 a relatively large share of the nutriment, and 

 is thus enabled to exert a greater pressure on 

 the contents of the cell. Its internal changes 

 are retarded or prevented, and the polar 

 body is held captive until some change per- 

 mits its escape. When the period of repro- 

 duction arrives, growth is no longer dominant 

 and the envelope is relatively weaker than 

 the forces making for reproduction. The egg 

 before the emission of the polar bodies has 

 gone through some of the changes that all 

 somatic cells undergo. In retracing its steps, 

 it throws off its epigenetic development and 

 comes back to its original state. If other 

 cells could be put through the same process, 

 they would in a like manner throw off their 

 complexities and be regenerated. Of this there 



