22 BOMBUS, APIS HAIRS ON BODY. [CHAP. 



little basket. Lastly in the Hive-bee (Fig. 28) the 

 adaptation is still more complete, the hairs on the 

 first tarsal segment are no longer scattered, but are 

 arranged in regular rows, and the tibial spurs, inherited 

 by Bombus from far distant ancestors, have entirely 

 disappeared. 



In some bees the pollen is collected on the body, 

 and here also we find a remarkable gradation from 

 Prosopis (Fig. 13) which has only simple hairs like a 



FIG. 27. Right hind-leg of Bombus FIG. 28. Right hind-leg of Hive-bee. 



Scrimshiranus. 



wasp ; through Sphecodes and Nomada, in which the 

 longer hairs are still few and generally simple (though 

 some few are feathered) ; to Andrena and Halictus 

 where the hairs are much more developed ; a change 

 which is still more marked in Saropoda, Colletes, 

 and Megachile ; still more so in Osmia and An- 

 thophora ; until we come to the Humble-bees, in 

 which the whole body h covered with long feathered 

 hairs. 



It is difficult to account for the relations which 



