REPRODUCTION 



183 



The isogamy is typically represented by the flagellate Copro- 

 monas subtilis (Fig. 78), in which there occurs, according to Dobell, 



Fig. 80. The life-cycle of Stephanosphaera pluvialis (Hieronymus). 

 a-e, asexual reproduction; f-m, sexual reproduction. 



a complete nuclear and cytoplasmic fusion between two isogametes. 

 Each nucleus, after casting off a portion of its nuclear material, 

 fuses with the other, thus forming a zygote containing a synkaryon. 

 In Trinerna lineare (Fig. 79), Dunkerly (1923) saw isogamy in which 



