358 CALIFORNIA ACADEMY OF SCIENCES. [Proc 3D Ser. 



EXPLANATION OF PLATE L. 



(Reduced about one-fourth). 



Fig. 7. Longitudinal section, not median, of young flower showing a lodic- 



ula, and stamen: X 320; lettered as above. 

 Cross-section of a young stamen: X 320. 

 Cross-section of a somewhat older stamen than that represented in 



the preceding figure: X 320. 

 Cross-section of stamen showing pollen mother-cells {pm): X 320. 

 Longitudinal section of stamen of the age shown in the preceding 



figure: X 320. 

 Section of pollen grain showing one vegetative and two generative 



nuclei: X 320. 

 Longitudinal section of ovule: X 320; o, outer integument; in, 



inner integument; ar, archesporial cell. 

 An ovule with nucellus {nu)\ and archesporial nucleus that has 



divided once (forming two sister nuclei): X 320. 

 Four sister nuclei: X 320. 



