66 BEES AND POLLEN-COLLECTING 



At the same time some species which have their 

 bodies clothed with branched hairs have simple 

 or spirally grooved hairs on the collecting organ 

 others collect on very much branched hairs 

 so that there seems to be no exact relationship 

 between the plumosity of the hairs and their 

 utility in collecting. The collecting brushes 

 are either on the hind legs or, as in some cases, 

 on the ventral surface of the body. In a female 

 Andrena, the hind leg has a tuft of curled hairs near 

 the base of the leg, and a more or less heavy 

 brush on the outside of the tibia or shin (fig. 8). 

 When a female returns after a collecting expedi- 

 tion these specially hairy regions are a mass 

 of pollen grains, and the " beautiful yellow 

 legs ", so often remarked upon in some bees, are 

 not always due to the colour of the hairs but 

 to that of the grains of pollen adhering to them. 

 The genera which collect on the under surface 

 of the body have to visit flowers where the 

 anthers lie in such a position that they can 

 transfer the pollen on to it ; the pea flower 

 tribe are favourites with them, and also the 

 Composite. All this section have long tongues 

 so that they are able to reach the nectaries of 



