i860.] FERTILISATION OF FLOWERS. 437 



use of all parts ? I fully believe that the structure of all 

 irregular flowers is governed in relation to insects. Insects 

 are the Lords of the floral (to quote the witty Athenaum) 

 world." 



He was probably attracted to the study of Orchids by 

 the fact that several kinds are common near Down. The 

 letters of i860 show that these plants occupied a good deal of 

 his attention ; and in 1861 he gave part of the summer and 

 and all the autumn to the subject. He evidently considered 

 himself idle for wasting time on Orchids, which ought to 

 have been given to 'Variation under Domestication.' Thus 

 he wrote : — 



" There is to me incomparably more interest in observing 

 than in writing ; but I feel quite guilty in trespassing on these 

 subjects, and not sticking to varieties of the confounded 

 cocks, hens and ducks. I hear that Lyell is savage at me. I 

 shall never resist Linum next summer." 



It was in the summer of i860 that he made out one of the 

 most striking and familiar facts in the book, namely, the 

 manner in which the pollen masses in Orchis are adapted 

 for removal by insects. He wrote to Sir J. D. Hooker July 

 12 : — 



"I have been examining Orchis pyramidalis, and it almost 

 equals, perhaps even beats, your Listera case ; the sticky 

 glands are congenitally united into a saddle-shaped organ, 

 which has great power of movement, and seizes hold of a 

 bristle (or proboscis) in an admirable manner, and then 

 another movement takes place in the pollen masses, by 

 which they are beautifully adapted to leave pollen on the 

 two lateral stigmatic surfaces. I never saw anything so beau- 

 tiful." 



In June of the same year he wrote : — 



"You speak of adaptation being rarely visible, though 

 present in plants. I have just recently been looking at the 

 common Orchis, and I declare I think its adaptations in 

 every part of the flower quite as beautiful and plain, or even 

 more beautiful than in the Woodpecker. I have written and 



