160 CHARLES DARWIX 



scientific world until the publication of Darwin's ' Origin 

 of Species,' half a century later. The same neglect 

 also overtook Sprengel's immensely interesting and 

 curious work on fertilisation of flowers. The world, in 

 fact, was not yet ready for the separate treatment of 

 functional problems connected with the interrelations 

 of organic beings ; so Knight and Sprengel were laid 

 aside unnoticed on the dusty top bookshelves of public 

 libraries, while the dry classificatory and systematic 

 biology of the moment had it all its own way for the 

 time being on the centre reading-tables. So many 

 separate and independent strands of thought does it 

 ultimately require to make up the grand final generalisa- 

 tion which the outer world attributes in its totality to 

 the one supreme organising intelligence. 



But in the ' Origin of Species ' itself Darwin 

 reiterated and emphasised Knight's law as a genera] 

 and all-pervading principle of nature, placing it at 

 the same time on broader and surer biological founda- 

 tions by affiliating it intimately upon his own 

 great illuminating and unifying doctrine of natural 

 selection. He also soon after rescued from oblivion 

 Sprengel's curious and fairy-like book, showing in full 

 detail in his work on orchids the wonderful contrivances 

 by which flowers seek to attract and to secure the assist- 

 ance of insects for the impregnation of their embryo 

 seeds. In the ' Variation of Animals and Plants under 

 Domestication,' he further showed that breeding in-and- 

 in diminishes the strength and productiveness of the 

 offspring ; while crossing with another stock produces, 

 on the contrary, the best possible physical results in 

 both directions. And now at last, in the ' Effects of 



