162 HOME STUDIES IN NATURE. 



bristles about the entrance of the utricle, which I find 

 in all of the species except in U. purpurea. So this 

 larva looks more like using its head as a wedge, but, as 

 we have seen, it is not at all necessary for it to use its 

 head in this manner. 



In a letter bearing date June 1, 1875, Mr. Darwin 

 says : " I have read your article with the greatest inter- 

 est. It certainly appears from your excellent observa- 

 tions that the valve was sensitive, and I hope it may be 

 so from homologizing with pinguicula; but I cannot 

 understand why I could never, with all my pains, ex- 

 cite any movement. It is pretty clear I am quite 

 ivrong about the head acting like a wedge. The in- 

 draught of the living larva is astonishing." 



