Fio. 21. — Lilium philaddphicvm. A, ovule before the appcaranee of integuments, 

 showing a single hypodermal arehesporial eell which is also the megaspore mother- 

 cell. -/>', beginning of inner integument. C, beginning of outer integument. D, E, 

 later stages, -F, 6?, the ovule anatropous and the megaspore germinating, x 175. 

 54 





