REPRODUCTIVE SYSTEM OF THE EARTHWORM 153 



of the anterior wall of the loth somite and another pair are 

 in the corresponding position on the anterior wall of the nth 



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



somite. When the sperm mother cells have reached a certain 

 stage of development they drop off the testis and continue their 



