294 



DICECIOUS AND 



Chap. VII. 



pary, he examined several male plants in the botanic 

 gardens at Konigsberg, where there were no females, and 

 sent me the accompanying drawings. 



Fig. 13. 



Long-styled male. 



Short-styled male. 



Khamnus catharticus. (From Caspary.) 



In the English plants the petals are not so greatly 

 reduced as represented in this drawing. My son ob- 

 served that those males which had their pistils moder- 

 ately well developed bore slightly larger flowers, and, 

 what is very remarkable, their pollen-grains exceeded 

 by a little in diameter those of the males with greatly 

 reduced pistils. This fact is opposed to the belief that 

 the present species was once heterostyled ; for in this 

 case it might have been expected that the shorter-styled 

 plants would have had larger pollen-grains. 



In the female plants the stamens are in an ex- 

 tremely rudimentary condition, much more so than 

 the pistils in the males. The pistil varies consid- 

 erably in length in the female plants, so that they 

 may be divided into two sub-forms according to the 

 length of this organ. Both the petals and sepals are 

 decidedly smaller in the females than in the males; 

 and the sepals do not turn downwards, as do those of 

 the male flowers when mature. All the flowers on the 

 same male or same female bush, though subject to 

 some variability, belong to the same sub-form; and 

 as my son never experienced any difficulty in decid- 





