1 88 PROBLEMS OF EVOLUTION 



though the same blossom bears both pistil and anthers. Since 

 cross-fertilisation is of advantage to them, it is likely that they 

 would develop some means of attracting insects as carriers. The 

 honey at once suggests itself as intended for this purpose. It 

 may appear sometimes as a waste product on the leaves of various 

 trees, where it is probably of no use to the plant. Its very 

 general presence in flowers must almost certainly serve some 

 useful purpose. That it is useful to the bee we know. But 

 generosity is not the rule among species whether vegetable or 

 animal, and we must, therefore, hold that the systematic produc- 

 tion of honey in large amounts brings some advantage to the 

 flower. The brilliant blossoms must surely act in the same way 

 as the honey. They must help to attract insects, which, while 

 occupied about their own business, are at the same time doing the 

 work of cross-fertilisation. If flowers are really useful in this way, 

 bees and other insect fertilisers must have some colour sense, 

 otherwise we should not see the blues, reds, purples, yellows 

 and whites of flowers standing out against the green foliage. 

 And if insects have a well-developed colour sense, then flowers 

 are most splendidly contrived advertisements or sign-boards. They 

 are far more beautiful than any advertisement devised by man ; 

 but to the insect for whom they were intended, I believe we may 

 say that they are simply conspicuous. The whole of his small 

 mind is intent upon his work, and there is no beauty unless there 

 is an eye to see it and appreciate it. It is enough for an insect to 

 see and recognise his flower. 



Red- The shapes of flowers show wonderful adaptations to the needs 

 procity o f i ns ects and other welcome visitors. The tube of the blossom 

 of some tropical plants follows the curve of the beak of the 

 particular humming bird for whom they cater probably he 

 extracts, not the honey, but the insects that are eating it. In 

 many of our common flowers there are converging lines which 

 seem well adapted to direct the bee to the nectary where the 

 honey is found. The flower of the common broom offers a fine 

 platform for the bee to alight upon, and the blossom does not 

 open till the insect comes and applies his weight. The many 

 hanging bell-flowers seem designed to keep out small unwelcome 



