284 A HISTORY OF GARDENING IN ENGLAND 



to greater importance. Of the work of these men and the 

 other eminent botanists of this century — Bentham, Lindley, 

 Brown, Smith, Loudon, Henslow, Sowerby, and the great 

 Darwin himself, and many others — it is impossible to speak 

 at length, but it is to men such as these that the wonderful 

 progress was due, to say nothing of those still living who 

 are looked up to with respect and admiration by practical 

 gardeners, not only in England itself, but throughout her vast 

 dominions. Men trained at Kew are in charge of Botanical 

 Gardens in every clime, and constant correspondence is kept 

 up with over eighty such gardens in British Colonies and India 

 alone. The work is ever increasing, and Kew is constantly 

 replenished with novelties from these sources. 



Nearly a hundred years before botanical researches were 

 carried on at Kew, scientists had been seeking to understand 

 the anatomy and sexes of plants, 1 and many practical gar- 

 deners, such as Philip Miller, Bradley, and Fairchild, had 

 succeeded in producing florists' varieties by hybridization, 

 although their knowledge was most imperfect. As early as 

 1793 Sprengel had put forth the theory 2 of cross fertilization, 

 but for forty years his suggestions were not followed up, and 

 it was not until Darwin devoted himself to unravelling the 

 mysteries, by long years of careful experiments, that the 

 wonders became perfectly understood. He gradually proved 

 that plants produced from cross fertilization were finer and 

 more robust than those which came from self-fertilized seed. 

 This was the case when the plants were dependent on the 

 visits of insects, but equally true when they did not require 

 their agency. The difference that could be effected in the vigour 

 of plants according to the way in which they had been fertilized 

 was thoroughly grasped after the fruits of Darwin's labours 

 were given to the world in 1876, 3 and within a few years, truths 

 which were undreamt of in 1830 were taught in elementary 

 textbooks. The gardener became possessed of a knowledge 

 the far-reaching effects of which it is impossible to estimate. 



1 See pp. 198-200, also 233. 



2 Das Entdeckte Geheimniss der Natur, 1793. 



3 Effects of Cross and Self Fertilization in the Vegetable Kingdom, by 

 Charles Darwin, 1876. 



