CHAP, i.] Joseph G. Koelreuter and Konrad SprengeL 409 



by which in the natural course of things the pollen finds its 

 way from the anthers to the stigmas. He ascribed perhaps too 

 much to the agency of the wind and the oscillations of the 

 flower from any cause ; at the same time he was the first 

 who recognised the great importance of the insect-world to 

 pollination in flowers. ' In flowers,' he says, ' in which pollin- 

 ation is not produced by immediate contact in the ordinary 

 way, insects are as a rule the agents employed to effect it,' 

 (later observation has shown that they are generally so 

 employed even in cases where actual contact is possible), 

 ' and consequently to bring about fertilisation also ; and it is 

 probable that they render this important service if not to the 

 majority of plants at least to a very large part of them, for 

 all the flowers of which we are speaking have something in 

 them which is agreeable to insects, and it is not easy to find 

 one such flower, which has not a number of these creatures 

 busy about it.' He noticed the dichogamous construction 

 in Epilobium, but did not further pursue his observation. He 

 next examined the substance in flowers which is agreeable to 

 insects ; he collected the nectar of many flowers in con- 

 siderable quantities, and found that it gave after evaporation 

 of the water a kind of sweet-tasted honey ; this honey was 

 unpalatable only in Fritillaria imperialis, which is avoided 

 by the humble-bees. He had no doubt therefore, that bees 

 procure their honey from the nectar of flowers. How greatly 

 he was interested in the relations between the existence of 

 certain plants and that of certain animals, relations which were 

 neglected till Darwin once more brought them into notice in 

 quite recent times, is shown by his investigation into the pro- 

 pagation of the mistletoe (1763) ; he calls special attention to 

 the fact, that not only must the pollination of this plant be 

 effected by insects, but that the dissemination of its seeds 

 is also exclusively the work of birds, and that the existence 

 of the plant therefore is dependent on two different classes 

 of living creatures. 



