104 BRITISH BEES. 



able, either from splendour, size, or remarkable eccen- 

 tricities of structure, are numerous. Tropical and sub- 

 tropical regions of course abound with them, in indivi- 

 duals, in species, and in genera ; and when we reflect upon 

 the riches of the flora of those countries, which is per- 

 petuated mainly by the agency of insects, amongst which, 

 in fulfilling this indispensable demand, bees, as I have 

 reiterated, are pre-eminently conspicuous, we shall not 

 even wonder that their number, although excessive in 

 the extreme, is considerably aided, in many cases, in 

 the performance of this task, by peculiarities of structure. 

 Thus, the splendid Brazilian genus Euglossa, although 

 not conspicuous for size, is remarkably so for the enor- 

 mous development of its posterior tibise, which form 

 very large triangles, compared with the size of the insect, 

 deeply hollowed for the conveyance of pollen. Its 

 tongue also, from the length of which the genus derives 

 its name, is, when extended, more than twice the length 

 of the body, and with which it is enabled to reach the 

 nectarium, seated within the depths of the longest tubes 

 of flowers. Other exotic bees, further to aid them in 

 collecting pollen, in addition to the dense brushes with 

 which their posterior legs are variously covered, have 

 each individual hair of these thick brushes considerably 

 thickened by hairs given ofi' laterally, and in some cases 

 these again ramify. Sometimes, in variation, the simple, 

 single hairs have a spiral curve, which almost equally 

 enlarges the activity of their operation. This is also the 

 case with two very hairy-legged genera of our native 

 bees, proximately allied to each other in the methodical 

 arrangement, Dasypoda and Panurgus, the hair of whose 

 posterior legs have this spiral twist. The most hairy- 

 legged exotic bees are essentially the genera Centris and 



