i.] BEES AND COLOURS. 15 



and among fly-flowers we find not only those which 

 attract the insects by honey or pollen, but also trap- 

 flowers, as, for instance, the Arum ; and deceptive 

 flowers, such as Parnassia, where five of the stamens 

 terminate in a number of beautiful yellow glands 

 which look like drops of honey, or Stapelia, in which 

 the flowers both in colour and smell resemble decay- 

 ing meat. 



That bees are attracted by, and can distinguish, 

 colours, was no doubt a just inference from the 

 observations on their relation to flowers, but I am 

 not cognisant of any direct evidence on the subject. 

 I thought it therefore worth while to make some ex- 

 periments ; and a selection from them will be recorded 

 in the forthcoming volume of the Journal of the 

 Linnean Society. I placed slips of glass with honey, 

 on papers of various colours, accustoming different 

 bees to visit special colours, and when they had made 

 a few visits to honey on paper of a particular colour, 

 I found that if the papers were transposed the bees 

 followed the colour. 



But if flowers have been modified with reference 

 to the visits of insects, insects also have in some cases 

 been gradually modified, so as to profit by their visits 

 to flowers. This is specially the case with reference 

 to two groups of insects, namely, Bees and Butter- 

 flies, which have been specially studied by H. Miiller 

 with reference to this point ; and from his works the 

 following facts are mainly taken. Although the 

 whole organisation of the insect might be said to 

 have reference to these relations, still the parts which 

 have been the most profoundly altered are the mouth 



