478 BEES AND FLOWERS. 



they extended their ])r<)I)()seides and (h'aiik in the same way they 

 collect nectar. 



Between these and the l^rosopis there is a long series in which we 

 may see the instruments for collecting nectar improve step by step. 

 With the Xylocoi)idae, the Antliophoridae, and the Eiigiossidae, we 

 arrive at the Mellifera, where the social life does not yet exist, hut 

 where the proboscis expuils in jierfection, and sometimes even sur- 

 passes, in development that of the connnon bee. Among the Euglos- 

 sidae it measures at least one and a half the length of the body. 



The collection of pollen is efl'ected by appendages which much 

 resemble those of the-Halictinae, only the hairs are short and more or 

 less brush-like on the leg as well as on the first joint of the tarsus. 

 These brushes api)roach those of the honeybee without attaining the 

 same degree of perfection, for the differentiations which make the 



Fio. 7.— The transportation of pollen by tho Mellifera. (The loads of ijollen are indicated by 



diagonal lines. ) 



1. A)idrena clarkeUu. 2. Apisiuelliji< a. S. Meijachileceuturicnlaiiis L. (Among the Megachiles, 



the pollen brush is on the ventral surface of the abdomen.) 



basket has not yet taken place, and the doul)le l)rush and the accom- 

 panying wrinkles must retain the pollen as well as collect it. 



One step more and we arrive at the hone}^ bee; here the brush on the 

 leg has been replaced by the basket and that of the first tarsal joint 

 serves only to collect the pollen dust. The insect no longer waits until 

 he reaches the nest to mix this dust with the honey, but at the moment 

 he collects he makes little balls wliich he carries in his basket. To 

 res])ond to the exigencies of the social life the honey gatherer accumu- 

 lates a reserve and has acquired a facidty of secreting a waxy mr.tler 

 Avliich allows him to construct cells. HowcYer, these aptitudes are l\y 

 no means equally developed in all llie forms of the group; at the foot 

 of the series are the bumble-bees who build without skill great ovoid 

 cells where they raise their young and store their reserves. These re- 

 serves are never large and often insufficient to provide for the colony 

 during the winter; this being the case, the colonies have a feeble coii- 



