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HUTCHINSON'S POPULAR BOTANY 



these flowers were 

 not once again sucked 

 by the bees, although 

 one actually crawled 

 over them. The re- 

 moval of the two 

 little upper petals 

 alone made no differ- 

 ence in their visits. 

 Mr. J. Anderson 

 states that when he 

 removed the corollas 

 of the Calceolaria, 

 bees never visited 

 the flowers." 



That this is not a 

 rule without excep- 

 tion, however, Dar- 

 win has himself 

 pointed out. He 

 shows clearly enough 

 that colour is not the 

 only insect guide, 

 and offers the com- 

 mon-sense sugges- 

 tion that insects may 

 be able "to recognize 

 plants even from a 

 distance by their general aspect, in the same manner as we should do." 

 We may add that the entire removal of the corollas of several flowers 

 of the Garden Convolvulus (Ipomwa purpurea) an experiment which we 

 tried not long since did not hinder bees from visiting those flowers; 

 indeed, they seemed to resort to them more freely than to the unmutilated 

 flowers, although the latter were fully expanded at the time. 



Sprengel's opinion has been quoted that " flowers differ in colour in 

 accordance with the kinds of insects which frequent them," and it would 

 be easy to bring forward an array of arguments in support of this view. 

 It has been noticed, for example, that the favourite colours of the honey- 

 bee are blue, violet, crimson, purple, and deep violet-blue, particularly 

 the last-named ; but that scarlet, orange, and yellow attract them but 

 little if at all. Possibly, as Kerner suggests, the nerve-bundles which 

 correspond to those colours are wanting in their eyes. Butterflies and 

 humble-bees, on the other hand, are very partial to scarlet. Scarlet appears 

 also to be the favourite colour of humming-birds ; and the fact is to be 



FIG. 482. SECTION OF PANSY FLOWER (Viola tricolor), 

 Showing spurred stamens projecting into the spur of the petal. The lateral petal will 

 be seen to have at its base a tuft of hairs which aid the bee in clinging to the (lower. 



