THE PLA^T GftOUPS 151 



far as possible the cellular structure and relations of the 

 following structures : 

 a. Megas2)orangia and female gametophyte. 



(1) If sections are available, study the female gameto- 



phyte, consisting of the egg apparatus, polar nuclei, 

 and antipodal cells. If such slides are not avail- 

 able, read the history of the development of the 

 megaspores in angiosperms in the text and com- 

 pare the history with that of megaspores in 

 Selaginella and the spruce. 



(2) Drawing. If sections are studied, draw and label 



the parts of the megasporangium, embryo sac, 

 and gametophyte cells. 



