1 874-] INSECTIVOROUS PLANTS. 3 2 5 



just like the helix of a human ear, if you were to stuff flies 

 within the fold. 



Yours most sincerely, 



Ch. Darwin. 



C. Darivin to Asa Gray. 



Down, June 3 [1874]. 



.... I am now hard at work getting my book on Drosera 

 & Co. ready for the printers, but it will take some time, for I 

 am always finding out new points to observe. I think you 

 will be interested by my observations on the digestive process 

 in Drosera ; the secretion contains an acid of the acetic series, 

 and some ferment closely analogous to, but not identical 

 with, pepsine ; for I have been making a long series of 

 comparative trials. No human being will believe what I 

 shall publish about the smallness of the doses of phosphate 

 of ammonia which act. 



.... I began reading the Madagascar squib * quite gravely, 

 and when I found it stated that Felis and Bos inhabited 

 Madagascar, I thought it was a false story, and did not 

 perceive it was a hoax till I came to the woman. . . . 



C. Darwin to F. C. Donders.\ 



Down, July 7, 1874. 



My dear Professor Donders, — My son George writes 

 to me that he has seen you, and that you have been very kind 

 to him, for which I return to you my cordial thanks. He 

 tells me on your authority, of a fact which interests me in 

 the highest degree, and which I much wish to be allowed to 

 quote. It relates to the action of one millionth of a grain of 

 atropine on the eye. Now will you be so kind, whenever you 

 can find a little leisure, to tell me whether you yourself have 



* A description of a carnivo- t Professor Donders, the well- 



rous plant supposed to subsist on known physiologist of Utrecht, 

 human beings. 



