I873-] FERTILISATION OF FLOWERS. 455 



vidual plants of Lobelia, &c, described by Gartner, and of 

 Passiflora and Orchids described by Mr. Scott. . . . 



Since writing to you before, I have read your admirable 

 memoir on Salvia, and it has interested me almost as much 

 as when I first investigated the structure of Orchids. Your 

 paper illustrates several points in my ' Origin of Species,' 

 especially the transition of organs. Knowing only two or 

 three species in the genus, I had often marvelled how one 

 cell of the anther could have been transformed into the mov- 

 able plate or spoon ; and how well you show the gradations ; 

 but I am surprised that you did not more strongly insist on 

 this point. 



I shall be still more surprised if you do not ultimately 

 come to the same belief with me, as shown by so many beau- 

 tiful contrivances, that all plants require, from some unknown 

 cause, to be occasionally fertilized by pollen from a distinct 

 individual. With sincere respect, believe me, my dear Sir, 



Yours very faithfully, 



Ch. Darwin. 



[The following letter refers to the late Hermann Miiller's 

 'Befruchtung der Blumen,' by far the most valuable of the 

 mass of literature originating in the ' Fertilisation of Orchids.' 

 An English translation, by Prof. D'Arcy Thompson was 

 published in 1883, My father's "Prefatory Notice" to this 

 work is dated February 6, 1882, and is therefore almost the 

 last of his writings :] 



C. Darwin to H. Miiller. 



Down, May 5, 1S73. 

 My dear Sir, — Owing to all sorts of interruptions and 

 to my reading German so slowly, I have read only to p. 88 of 

 your book ; but 1 must have the pleasure of telling you how 

 very valuable a work it appears to me. Independently of the 

 many original observations, which of course form the most 

 important part, the work will be of the highest use as a means 

 of reference to all that has been done on the subject. I am 



