ANDRENID2E. AFIDJE. *169 



organs are employed for the purpose of collecting and carrying 



the pollen of flowers, which is destined for the nourishment 



of the young. All the insects of this 



tribe are commonly known by the name of 



Bees ; but the tribe, like that of Wasps, 



contains two different groups, in one of 



which the species are all solitary, and there 



are only two kinds of individuals males 



and females in each ; whilst the others 



often live in societies of greater or less 



extent, but are chiefly distinguished from 



the former by certain peculiarities in the 



structure of the mouth. 



763. In the Bees which constitute the family ANDRENID^E, 

 the tongue is short, and blunt at the extremity, and the mentum 

 or chin is elongated. They are always solitary in their habits ; 

 the females form burrows in the ground, usually in sandy places, 

 and provision these with masses of pollen and honey, in the 

 midst of which they deposit their eggs. Each nest contains 

 several such masses, each provided with an egg, and separated 

 from its neighbours by small partitions of earth. The perfect 

 Bees usually make their appearance in the spring. 



764. The APID.E, or True Bees, are distinguished from the 

 preceding by the great length of the tongue-, which exhibits the 

 structure described in 672. Their habits are very various and 

 exceedingly interesting, their nests being constructed of the most 

 different materials, and often displaying great ingenuity. Many 

 of them burrow in the ground in the same way as the Bees of 

 the preceding family ; others, known as Mason Bees, build a 

 small edifice, consisting of several cells, with grains of sand or 

 gravel, which they fasten together with a viscid saliva ; the 

 Carpenter Bees (Fig. 490) form their cells in dead wood, 

 which they excavate with their powerful jaws ; whilst the Up- 

 holsterer Bees construct their nests with pieces of leaves, which 

 they cut into the requisite form with surprising dexterity. The 

 purpose of these operations is, in all instances, to form a series 

 of cells, in each of which an egg is deposited, with a supply of 



