490 CLIMBING AND INSECTIVOROUS PLANTS. [i860. 



tinued ill-health, and it was now found to require a great 

 deal of alteration. He wrote to Sir J. D. Hooker (March 3, 

 1875) : " It is lucky for authors in general that they do not 

 require such dreadful work in merely licking what they write 

 into shape." And to Mr. Murray in September he wrote : 

 "The corrections are heavy in ' Climbing Plants,' and yet I 

 deliberately went over the MS. and old sheets three times." 

 The book was published in September 1875, an edition of 

 1500 copies was struck off; the edition sold fairly well, and 

 500 additional copies were printed in June of the following 

 year.] 



INSECTIVOROUS PLANTS. 



[In the summer of i860 he was staying at the house of his 

 sister-in-law, Miss Wedgwood, in Ashdown Forest, whence he 

 wrote (July 29, i860), 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' (vol. i. p. 77), 

 the general 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 suspected that the leaves were adapted to supply nitro- 

 genous food to the plant. He therefore tried the effect on 

 the leaves of various nitrogenous fluids — with results which, 

 as far as they went, verified his surmise. In September, 

 i860, he wrote to Dr. Gray : — 



" I have been infinitely amused by working at Drosera : 

 the movements are really curious ; and the manner in which 

 the leaves detect certain nitrogenous compounds is marvel- 



