66 A TEXTBOOK OF THEORETICAL BOTANY 



colony the cells enlarge somewhat and become the female gametes, or 

 oospheres, which, when mature, are fertilized in situ. In male colonies the 



Mucilaginous 

 envelope 



Group of sterile 

 cells 



Fig. 42. — Etidorina illinoisetnis. \^egetative 

 colony showing the four small cells at the 

 posterior end which do not reproduce. 





Daughter colony 



Sterile cells A • • 



KiG. 43. — Eudorina il/inoisensis. Reproduction 

 colony showing daughter colonies form- 

 ing in all cells except the four posterior 

 cells. 



cells divide to form groups of sixty-four antherozoids, yellowish in colour, 

 and each with two flagella. These are liberated as groups which swim to the 

 female colonies, where the antherozoids separate. The zygotes germinate as 

 in Pandorina. 



