THE HUMBLE BEES 43 



again we find a quite different form ; entirely 

 black except for the bright red hairs on the apex 

 of the body, and bright red tibiae, clothed with 

 red hairs. In the Canaries another coloration 

 occurs : the whole bisect is black with the excep- 

 tion of the apex of the body which is clothed 

 with white hairs ; but in all these the male 

 varies comparatively little. In the Siberian 

 and Canary forms it resembles the female, but 

 in the others it varies very little from some 

 varieties we find here. A rather similar series 

 of varieties occurs in Bombus hortorum, another 

 species little liable to variation here. In Italy 

 and south-east Europe a form with entirely 

 black body and black wings occurs, and in 

 Corsica a black form with reddish hairs on the 

 apical segments. The male keeps throughout 

 very constant to its normal coloration. The 

 tendency to vary towards an entirely black form 

 seems to exist in nearly all the species, although 

 in Britain black varieties of some are very rare. 



