303 'DIFFERENT FORMS OF FLOWERS [1862. 



never shed, or never leave the anther-cells, but emit long 

 pollen tubes, which penetrate the stigma. To-day I got the 

 anther with the included pollen grain (now empty) at one 

 end, and a bundle of tubes penetrating the stigmatic tissue at 

 the other end ; I got the whole under a microscope without 

 breaking the tubes ; I wonder whether the stigma pours some 

 fluid into the anther so as to excite the included grains. It is 

 a rather odd case of correlation, that in the double sweet 

 violet the little flowers are double ; i.e., have a multitude of 

 minute scales representing the petals. What queer little 

 flowers they are. 



Have you had time to read poor dear Henslow's life? 

 it has interested me for the man's sake, and, what I did 

 not think possible, has even exalted his character in my 

 estimation 



[The following is an extract from the letter given in part 

 at p. 303, and refers to Dr. Gray's article on the sexual 

 differences of plants :] 



C. Darwin to Asa Gray. 



November 26 [1862]. 



.... You will think that I am in the most unpleasant, con- 

 tradictory, fractious humour, when I tell you that I do not like 

 your term of " precocious fertilisation " for your second class 

 of dimorphism [i.e. for cleistogamic fertilisation]. If I can 

 trust my memory, the state of the corolla, of the stigma, and 

 the pollen-grains is different from the state of the parts in the 

 bud ; that they are in a condition of special modification. 

 But upon my life I am ashamed of myself to differ so much 

 from my betters on this head. The temporary theory* which 

 I have formed on this class of dimorphism, just to guide 

 experiment, is that the perfect flowers can only be perfectly 



* This view is now generally accepted. 



