270 SPERMATOGENESIS AND . OOGENESIS LESS, xxiv 



a single ovum : the protoplasm of others divides repeatedly 

 and forms aggregations of sperms (B, spy^ spy' , spy", and 

 Fig. 66, s). By the conjugation of a sperm (F) with an 

 ovum (G) an oosperm (H) is produced, and from this by 

 continued division a new colony arises. 



Volvox is clearly comparable to a hollow polyplast, and 

 further resembles the higher or multicellular animals in 

 that certain of its cells are differentiated to form true sexual 

 products. 



