204 THE EVOLUTION THEORY 



withdrew so many flowers from the influence of the effective 

 pollinating visitor, the bee, that too few seeds were formed, and the 

 survival of the species was threatened by the continual dwindling of 

 the normal number. As long as the bees visit the flowers frequently 

 enough to ensure the formation of the necessary number of seeds 

 a process of selection could not set in ; but should the bees find, for 

 instance, that nearly all the flowers had been robbed of their nectar, 

 and should therefore visit them less diligently, then every variation of 

 the flower which made honey less accessible to the butterflies would 

 become the objective of a process of selection. 



Everywhere we find similar imperfections of adaptation which 

 indicate that they must depend on processes of selection. Thus 

 numerous flowers are visited by insects other than those which 

 pollinate them, and these bring them no advantage, but merely rob 

 them of nectar and pollen ; the most beautiful contrivances of many 

 flowers, such as Glycinia, which are directed towards cross-fertilization 

 by bees, are rendered of no effect because wood-bees and humble-bees 

 bite holes into the nectaries from the outside, and so reach the nectar 

 by the shortest way. I do not know whether bees in the native 

 land of the Glycinia do the same thing, but in any case they can do 

 no sensible injury to the species, since otherwise processes of selection 

 would have set in which would have prevented the damage in some 

 way or other, whether by the production of stinging-hairs, or hairs 

 with a burning secretion, or in some other way. If the actual 

 constitution of the plant made this impossible, the species would 

 become less abundant and would gradually die out. 



Thus the relative imperfection of the flower-adaptations, which 

 in general are so worthy of admiration, affords a further indication 

 that their origin is due to processes of selection. 



ADDITIONAL NOTE TO CHAPTER X. 



It has been remarked that the chapter on the Origin of Flowers 

 in the German Edition contains no discussion and refutation of the 

 objections which have up till recently been urged against the theory 

 of flowers propounded by Darwin and Hermann Muller. I admit 

 that this chapter seemed to be so harmonious and so well rounded, 

 and at the same time so convincing as to the reality of the processes 

 of selection, that the feeble objections to it, and the attempts of 

 opponents to find another explanation of the phenomena, might well 

 be disregarded in this book. 



However, the most important of these objections and counter- 

 theories may here be briefly mentioned. 



