BEES AND POLLEN-COLLECTING 69 



(it may possibly be used for other purposes too) 

 is a still more wonderful adaptation ; in the 

 basal joint of the foot there is a semicircular 

 incision, which, when examined under the micro- 

 scope, is seen to be a small toothed comb. The 

 foot itself fits into the tibia or shin, and at the 

 apex of the latter is a modified spine which is 



FIG. 10. FIG. 11. FIG. 12. 



dilated on one side into a wing, or knife-like 

 blade ; this shuts down on to the semicircular 

 comb, and the insect by passing the antennae be- 

 tween the two can clean off anything which may 

 have stuck to it (fig. 11). When we come to ex- 

 amine the other legs we find that the inner surface 

 of their tibiae and tarsi, i.e. that which is nearest 

 the body, is clothed with hairs which have the 

 points dilated and spade-like (fig. 12), which allow- 



