340 BOTANY. [ch. xvii. 



manner in which you have treated me and my mistakes, I 

 remain, 



My dear Sir, yours sincerely. 



Insectivorous Plants. 



In the summer of 1860 he was staying at the house of 

 his sister-in-law, Miss Wedgwood, in Ashdown Forest, 

 whence he wrote (July 29, 1860) to Sir Joseph Hooker : 



" Latterly I have done nothing here ; but at first I 

 amused myself with a few observations on the insect-catch- 

 ing power of Drosera : * and I must consult you some time 

 whether my ' twaddle ' is worth communicating to the Lin- 

 nean Society." 



In August he wrote to the same friend : 



" I will gratefully send my notes on Drosera when copied 

 by my copier : the subject amused me when I had nothing 

 to do." 



He has described in the Autobiography (p. 47), the gen- 

 eral nature of these early experiments. He noticed insects 

 sticking to the leaves, and finding that flies, &c, placed on 

 the adhesive glands, were held fast and embraced, he sus- 

 pected that the captured prey was digested and absorbed by 

 the leaves. He therefore tried the effect on the leaves of vari- 

 ous nitrogenous fluids with results which, as far as they 

 went, verified his surmise. In September, 1860, he wrote 

 to Dr. Gray : 



" I have been infinitely amused by working at Drosera : 

 the movements are really curious ; and the manner m which 

 the leaves detect certain nitrogenous compounds is marvel- 

 lous. You will laugh ; but it is, at present, my full belief 

 (after endless experiments) that they detect (and move in 

 consequence of) the 2 ^ 80 part of a single grain of nitrate of 

 ammonia ; but the muriate and sulphate of ammonia bother 

 their chemical skill, and they cannot make anything of the 

 nitrogen in these salts ! " 



Later in the autumn he was again obliged to leave home 

 for Eastbourne, where he continued his work on Drosera. 



On his return home he wrote to Lyell (November 

 1860) : 



" I will and must finish my Drosera MS., which will 

 take me a week, for, at the present moment, I care more 



* The common sun-dew. 



