2$8 FERTILISATION [1839. 



intercrossing of distinct plants lies the key to the whole 

 question. Hermann Miiller has well remarked that this 

 " omission was for several generations fatal to Sprengel's 

 work. .... For both at the time and subsequently, botanists 

 felt above all the weakness of his theory, and they set aside, 

 along with his defective ideas, his rich store of patient and 

 acute observations and his comprehensive and accurate inter- 

 pretations." It remained for my father to convince the world 

 that the meaning hidden in the structure of flowers was to 

 be found by seeking light in the same direction in which 

 Sprengel, seventy years before, had laboured. Robert Brown 

 was the connecting link between them ; for although, accord- 

 ing to Dr. Gray, * Brown, in common with the rest of the 

 world, looked on Sprengel's ideas as fantastic, yet it was at 

 his recommendation that my father in 1841 read Sprengel's 

 now celebrated ' Secret of Nature Displayed. \ The book 

 impressed him as being " full of truth," although " with some 

 little nonsense." It not only encouraged him in kindred 

 speculation, but guided him in his work, for in 1844 he 

 speaks of verifying Sprengel's observations. It may be 

 doubted whether Robert Brown ever planted a more fruitful 

 seed than in putting such a book into such hands. 



A passage in the * Autobiography ' (vol. i. p. 90) shows 

 how it was that my father was attracted to the subject of 

 fertilisation: "During the summer of 1839, and I believe 

 during the previous summer, I was led to attend to the 

 cross-fertilisation of flowers by the aid of insects, from 

 having come to the conclusion in my speculations on the 

 origin of species, that crossing played an important part in 

 keeping specific forms constant." 



The original connection between the study of flowers and 

 the problem of Evolution is curious, and could hardly have 

 been predicted. Moreover, it was not a permanent bond. 



* ' Nature,' 1874, p. 80. Natur im Baue und in der Befruch- 



f 'Das entdeckte Geheimniss der tung der Blumen.' Berlin, 1793. 



