POLLINATION 119 



like pile of short hairs, and usually secretes a sticky, 

 sugary excretion features which subserve the same end. 



This so-called anemophilous pollination is uncertain 

 and wasteful and has in many cases been superseded by 

 the intervention of insects. Hence we find developed 

 the colour, fragrance, and other attractions which 

 flowers so generally possess. Colour and fragrance cause 

 conspicuousness, and appeal to insect visitors. The 

 latter seek, of course, more substantial benefits than 

 these, regarding the flowers as the seats of supplies of 

 nutritive substances which they require. While they 

 rifle the flowers of both pollen and honey, they inad- 

 vertently serve their turn by transferring the pollen 

 from the stamens of one flower to the stigma of another. 



The relations that have thus come to be so widely 

 established have probably grown up very gradually and 

 in an infinite variety of ways. Different insects visit 

 different flowers and the influence of the particular kind 

 of insect visitor explains the manner of modification 

 which the particular flower has undergone. The modi- 

 fications are almost infinite in variety and we can only 

 here deal with them in a very general way. 



The earliest modifications, which were only slight, 

 were associated with the discovery by certain lowly 

 insects that pollen itself formed nutritious food. The 

 flower was widely open, the perianth leaves spreading 

 symmetrically round the axis below the stamens, and 

 the latter opened and let their pollen fall. A slight 

 change of colour, probably from green to yellow or 

 white, made the flowers sufficiently conspicuous, and 

 the visits of the insects followed. 



But a further attraction was afforded later by the 

 formation and storage of honey in the flower. It is 

 impossible to discuss this subject in detail as it has 

 exhibited such infinite variety of modification. The 

 storage of honey led to the development of pocket-like 



