SPERM ATOGENESIS OF THE EARTHWORM 157 



The nuclei increase by division and take a position at the periphery of the 

 protoplasmic mass, where further multiplication follows until there are 

 from 32 to 64 nuclei. Protoplasmic furrows then cut in around each of 



FIG. 64. Stages in the development of spermatozoa of the earthworm. 

 (From Calkins.) 



the peripheral nuclei. Each of these nuclei then begins to elongate, and 

 to transform into a spermatozoon. The nucleus forms the head of the 



