ON BEES' WINGS 



THE Bees and the other stinging groups have four 

 wings like all the Hymenoptera. These wings 

 are almost always clear and transparent, at 

 any rate amongst the British species, there 

 being only one exception which I can call to 

 mind in the female of the cuckoo of our large 

 red-tailed humble-bee, which has the wings 

 blackish ; also they are never spotted, as in some 

 flies. The hind or lower wings unite with the 

 upper by a series of very beautiful hooks which 

 extend along their upper margin and fix on 

 to the posterior edge of the front wing, which is 

 folded back on itself so as to receive them ; in 

 flight the two wings are united, but when at 

 rest they separate ; these hooks are beautiful 

 objects under a microscope ; their numbers vary ; 

 and in some cases this variation is useful in distin- 

 guishing closely allied species from one another. 

 The hum of a bee is caused, to a great extent, by 



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