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 
I 793 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 dev Natur, 1793. 
3 Effects of Cross and Self Fertilization in the Vegetable Kingdom, by 
Charles Darwin, 1876. 
