1 868.] ON PLANTS OF THE SAME SPECIES.' 307 



from the common oxlip, except by the length of the seed- 

 capsule relatively to the calyx. This seems to me rather a 

 horrid fact for all systematic botanists 



C. Darwin to F. Hildebrand. 



Down, November 16, 1868. 



My DEAR Sir, — I wrote my last note in such a hurry from 

 London, that I quite forgot what I chiefly wished to say, 

 namely to thank you for your excellent notices in the ' Bot. 

 Zeitung ' of my paper on the offspring of dimorphic plants. 

 The subject is so obscure that I did not expect that any one 

 would have noticed my paper, and I am accordingly very 

 much pleased that you should have brought the subject 

 before the many excellent naturalists of Germany. 



Of all the German authors (but they are not many) whose 

 works I have read, you write by far the clearest style, but 

 whether this is a compliment to a German writer I do not 

 know. 



[The two following letters refer to the small bud-like 

 " Cleistogamic " flowers found in the violet and many other 

 plants. They do not open and are necessarily self-fertilised :] 



C. Darwin to J. D. Hooker. 



Down, May 30 [1862]. 



.... What will become of my book on Variation ? I am 

 involved in a multiplicity of experiments. I have been 

 amusing myself by looking at the small flowers of Viola. If 

 Oliver * has had time to study them, he will have seen the 

 curious case (as it seems to me) which I have just made 

 clearly out, viz. that in these flowers, the few pollen grains are 



* Shortly afterwards he wrote : with most accurate description of 

 " Oliver, the omniscient, has sent all that I saw in Viola." 

 me a paper in the ' Bot. Zeitung,' 



X 2 



