COXJUGA T.-E 



261 



another and meet ; the septum between them disappears ; the endo- 

 chromes of the two cells draw towards one another and coalesce, with 

 condensation of the protoplasm, in the connecting tube thus formed (fig. 

 235). In ]M. neaumensis (Bennett, Journ. ISIicr. Soc, 1S86, p. 15) the 





Fig. i^-^.—Mesocarpiis par^mlus Hass. ; 

 stages in the formation of zj-gosperm 

 ( >< 750)- (After de Bary.) 



Fig. 234. — Staurospermuvi gracilliinmn 

 Hass., with quadrate zygosperms, showing 

 axile plate of chlorophyll in the cells which 

 have not conjugated (x 400). (From) 

 nature.) 



zygosperm is not formed in the connecting tube, but in one of the con- 

 jugating cells. In Gonatonema (Wittr.) parthe?iosperms are said to 

 be formed closely resembling zygosperms, but not resulting from the 



