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CHARLES PACKARD 



ment. Variations from this rate are small if the temperature 

 remains constant. It will be seen that the sperm remains ex- 

 ternal to the egg during the prophase and the early formation of 

 the first maturation spindle, and does not begin to enter until 

 the time of the first anaphase. At that time it is drawn through 

 the membrane, a process which occupies less than 5 minutes. 

 It continues its course inward during the first telophase, and is 



TABLE 1 

 Shoioing the development of Nereis eggs radiated before insemination 



