DIFFERENTIATION OF GAMETES 



211 



in some species, for instance the cells forming male 

 gametes are sometimes shorter than those forming the 



FIG. 32. A and B, two stages of development of the zygote of a 

 species of Spirogyra in which the wall is transparent and the 

 chloroplast of the male gamete is degenerating and breaking 

 up. The chloroplast of the female gamete alone produces the 

 chloroplasts of the cells of the new individual, x 800 (after 

 Chmielevsky) . C, germination of zygote : two cells of the new 

 individual are produced. X 395. 



females, and in other cases the conjugation canal is 

 mainly or even wholly formed by the male conjugating 

 cell, the female cell merely swelling up to meet it. 



