206 BRITISH BEES. 



and it proceeds to the elaboration of another receptacle 

 for a fresh brood until its stock of eggs becomes ex- 

 hausted. Some species have two broods hatched in the 

 year, especially the earlier ones, for several present 

 themselves with the earliest flowers, but others are re- 

 stricted to but one. The quantity of pollen they col- 

 lect is considerable, and in fact they are supplied with 

 an apparatus additional to what is furnished to any of 

 the other genera in a curled rather long lock of hair 

 that emanates from the posterior trochanters. This, with 

 the fringes that edge the lower portion and sides of the 

 metathorax, as well as the usual apparatus upon the 

 posterior legs, enables the insect to carry in each flight 

 home a comparatively large quantity of pollen, but per- 

 haps scarcely enough at once for the nurture of one 

 young one, and it therefore repeats the same operation 

 until sufficient is accumulated. 



The exact period occupied by their transformations is 

 not strictly known ; it will, of course, vary in the spe- 

 cies, as also in those in which two broods succeed each 

 other in the year, but the larva rapidly consumes its 

 store and then undergoes its transformation. It does 

 not spin a cocoon, but in its pupa state it is covered 

 all over with a thin pellicle, which adheres closely to 

 all the distinct parts of the body. It is not known how 

 this is formed; perhaps it is a membrane which trans- 

 udes in a secretion through the skin of the larva, or it 

 may be this itself converted to its new use, which seems 

 to be for the protection of all the parts of the now 

 transmuting imago, until these in due course shall have 

 acquired their proper consistency. 



These insects in their perfect state vary very consi- 

 derably in size, both individually and specifically, the 



