472 'DIFFERENT FORMS OF FLOWERS [1860, 



I have now examined primroses and find exactly the same 

 difference in the size of the pollen, correlated with the same 

 difference in the length of the style and roughness of the 

 stigmas. 



C. Darwin to Asa Gray. 



June 8 [1860]. 



.... I have been making some little trifling observations 

 which have interested and perplexed me much. I find with 

 primroses and cowslips, that about an equal number of plants 

 are thus characterised. 



So-called (by me) male plant. Pistil much shorter than 

 stamens ; stigma rather smooth, -pollen grains large, throat 

 of corolla short. 



So-called female plant. Pistil much longer than stamens, 

 stigma rougher, pollen-grains smaller, throat of corolla long. 



I have marked a lot of plants, and expected to find the so- 

 called male plant barren ; but judging from the feel of the 

 capsules, this is not the case, and I am very much surprised at 

 the difference in the size of the pollen. ... If it should 

 prove that the so-called male plants produce less seed than 

 the so-called females, what a beautiful case of gradation from 

 hermaphrodite to unisexual condition it will be ! If they pro- 

 duce about equal number of seed, how perplexing it will be. 



C. Darwin to J. D. Hooker. 



Down, December 17, [1863?] 



.... I have just been ordering a photograph of myself for 

 a friend ; and have ordered one for you, and for heaven's sake 

 oblige me, and burn that now hanging up in your room. It 

 makes me look atrociously wicked. 



.... In the spring I must get you to look for long pistils 

 and short pistils in the rarer species of Primula and in some 

 allied Genera. It holds with P. Sinensis. You remember 

 all the fuss I made on this subject last spring ; well, the other 

 day at last I had time to weigh the seeds, and by Jove the 

 plants of primroses and cowslip with short pistils and large 



