460 FERTILISATION OF FLOWERS. [187S. 



ceae, &c. ; but I have been delighted with what you say on the 

 conversion of a monoecious species into a hermaphiodite one 

 by the condensations of the verticils on a branch bearing 

 female flowers near the summit, and male flowers below. 



I expect Hooker to come here before long, and I will then 

 show him your drawing, and if he makes any important re- 

 marks I will communicate with you. He is very busy at 

 present in clearing off arrears after his American Expedition, 

 so that I do not like to trouble him, even with the briefest 

 note. I am at present working with my son at some Physio- 

 logical subjects, and we are arriving at very curious results, 

 but they are not as yet sufficiently certain to be worth com- 

 municating to you. . . . 



[In 1877 a second edition of the * Fertilisation of Orchids' 

 was published, the first edition having been for some time out 

 of print. The new edition was remodelled and almost re- 

 written, and a large amount of new matter added, much of 

 which the author owed to his friend Fritz Miiller. 



With regard to this edition he wrote to Dr. Gray : — 



" I do not suppose I shall ever again touch the book. 

 After much doubt I have resolved to act in this way with all 

 my books for the future ; that is to correct them once and 

 never touch them again, so as to use the small quantity of 

 work left in me for new matter." 



He may have felt a diminution of his powers of reviewing 

 large bodies of facts, such as would be needed in the prepa- 

 ration of new editions, but his powers of observation were 

 certainly not diminished. He wrote to Mr. Dyer on July 14, 

 1878:] 



My dear Dyer, — 2'halia dealbata was sent me from Kew : 

 it has flowered and after looking casually at the flowers, they 

 have driven me almost mad, and I have worked at them for 

 a week : it is as grand a case as that of Catasetum. 



Pistil vigorously motile (so that whole flower shakes when 

 pistil suddenly coils up) ; when excited by a touch the two 



