52 DARWINISM AND HUMAN LIFE 



tilising golden dust from blossom to blossom, so 

 that the possible seeds become real seeds. 



In 1793 a Berlin naturalist, Christian Konrad 

 Sprengel, like Darwin in his perception of the 

 web of life, published a pioneer book entitled 

 " The Secret of Nature discovered in the Structure 

 and Fertilisation of Flowers," in which he showed 

 that most flowers have nectar which insects 

 enjoy; that by the insects' visits pollination is 

 secured ; that there is no detail of the flower without 

 its meaning the colour is a flag to attract the 

 insect's eye, conspicuous spots are honey-guides 

 to the explorers, there are arrangements for keeping 

 the pollen dry and for dusting it on the insects, 

 and so on. If Sprengel had only discovered the 

 utility of the cross-fertilisation, which Darwin 

 proved experimentally, his work could hardly 

 have been overlooked for nearly seventy years. 

 In 1841 it came into Darwin's hands, and im- 

 pressed him as being " full of truth," although 

 " with some little nonsense." In Darwin's work 

 Sprengel had his long-delayed reward. 



DARWIN'S INSTANCE OF THE CONNECTION BE- 

 TWEEN CATS AND CLOVER. One of Darwin's 

 instances of the web of life given in connection 

 with the pollination of flowers has become 

 familiar all over the world. It should never 

 become trite to us and it should never be regarded 

 as more than a particularly clear illustration of 

 a general fact. " Plants and animals, remote in 

 the scale of nature, are bound together by a web 

 of complex relations. ... I have found, from 

 experiments, that humble-bees are almost indis- 

 pensable to the fertilisation of the heart 's-ease 

 (Viola tricolor), for other bees do not visit this 



