330 THE WORLD OF LIFE 



from having as yet found no exception to the rule that seeds 

 are always thus disseminated when embedded within a fruit 

 of any kind if it be coloured of any brilliant tint." ^ 



Such general statements as those here quoted do not make 

 much impression. The astonishment and delight of botanists 

 and plant-lovers can, therefore, be imagined when, a few years 

 later, by his book on the Fertilisation of Orchids by Insects, 

 and his papers on the Different Forms of Flowers in the prim- 

 rose, flax, lythrum, and some others ; he opened up a vast new 

 world of wonder and instruction which had hitherto remained 

 almost unnoticed. These were followed up by his volumes 

 on The Effects of Cross- and Self -Fertilisation (in 1876), 

 and by that on Different Forms of Flowers on Plants of the 

 same Species (in 1877) giving the result of hundreds of care- 

 ful experiments made by himself during many years, serv'ing 

 as the justification for the few general observations as regards 

 flowers and insects, which form the only reference to the sub- 

 ject in the Origin of Species. 



The facts now admitted to be established by these various 

 researches are: (1) that crosses between different individuals 

 of the same species, either constantly or occasionally, are ben- 

 eficial to the species by increasing seed-production and vigour 

 of growth; (2) that there are innumerable adaptations in 

 flowers to secure or facilitate this cross-fertilisation; (3) that 

 all irregular flowers — Papilionacese, Labiates, Schrophulari- 

 acese, Orchidese, and others — have become thus shaped to facil- 

 itate cross-fertilisation. Darwin's general conclusion, that 

 " nature abhors perpetual self-fertilisation," has been much 

 criticised, but chiefly by writers who have overlooked the term 

 " perpetual." He has also shown how the wonderful variety 

 in form and structure, and the beauty or conspicuousness of 

 the colours of flowers, can all be readily explained, on this 

 theory, through the agency of variation and natural selection, 

 while by no other theory is any real and effective explanation 

 possible. But besides these there are very numerous other 



1 Origin of Species, 6th edition, p. 161. 



