Fig. noi.-Taxm baccato. Development of the megaspore. A Arche- 

 sporial mother cell m the nucellus B to D, Development o the 

 archesporium. E, Development of primary sporogenous cells at 

 Te lower ends of 'rows of archesporial cells. F, Meiotic dmsion of 

 a sporogenous cell which functions as a megaspore mother cell. 

 G, Row of four megaspores, upper three abortive, lowest developing 

 into embryo sac. (After Dupler.) 



