Flowers 



From that distant time until to-day every change in 

 colour or in form has had to be exposed to the insect's 

 eye. Those changes which found most favour have 

 been perpetuated. 



In this process there is nothing at all more mysterious 

 than the selection exercised by those nurserymen who 

 produce yearly new varieties of turnips or potatoes, but 

 it is the insects who select and discard (see p. 285). 



Not long ago the scientific world was alarmed and 

 disturbed by a certain botanist, who declared that insects 

 were not attracted by colour but by scent. 



Proof, though not in the least required by any of 

 those who had studied the question, was very soon forth- 

 coming. When one single petal of a composite could 

 attract bees, it was of course obvious that neither scent 

 nor the shape of the flower, but colour alone, was the 

 important point.^^ 



An observation of Dr. Ridley's is too interesting to 

 leave out ; it reminds us of certain Athenian birds which 

 pecked at Apelles' pictures. 



Dr. Ridley, when passing through the Suez Canal, 

 happened to be in the smoking-room of the steamer, 

 which was decorated with white enamelled tiles on 

 which flowers were represented. Some of these were 

 " cup-shaped, more or less resembling a tulip," and the 

 alternate ones were conventional composites. Certain 

 ** humming-bird hawk " moths were in the smoking- 

 room, and he noticed that they were trying to probe 

 the mouths of these conventional flowers. As they 

 had no scent of any sort or kind, it is clear that the 

 moths were attracted by the colour.^^ 



But this would never have been doubted by any 

 one who had taken the trouble to watch for insect- 

 visitors on wild plants when growing in their natural 

 homes. 



115 



