MOUTH-PARTS, WINGS, AND LEGS 55 



flies are clothed with hairs, and are used as toilet brushes 

 for removing dust from the insect's eyes and face. The 

 Nymphaline butterflies, of which our peacocks and red- 

 admirals are good examples, have for this reason been 

 termed " brush-footed." The most wonderful contri- 

 vances, however, are found on the hind-legs of pollen- 

 gathering bees, especially the hive-bee. In the latter 

 insect, the proximal segment of the tarsus — i.e. that which 

 is joined to the tibia or shin — is as long as all the rest 

 put together, and very broad. It is called the planta or 

 metatarsus. Its inner surface is beset with ten trans- 

 verse rows of stout hairs or bristles, which are used 

 for combing the pollen out of the insect's hairs. The 

 tibia, on its outer face, has a longitudinal concavity 

 — the corbiculum or pollen basket — which is fringed with 

 recurved hairs ; and in this the pollen is packed for trans- 

 port. The broad, sharp edges at the juncture of the tibia 

 and planta are used as nippers for holding and cutting 

 wax. The foregoing remarks apply exclusively to the 

 "worker" bee. The hind-legs of the queen, and of the 

 drones or males, not being used for pollen-collecting, are 

 destitute of baskets, pincers and combs, and are shaped 

 differently. 



Many insects which walk with their tarsal segments 

 flat upon the ground have the under surface of these 

 joints broadened to afford support ; while there is often 

 a cushion-like pad, called the pulvillus, between the bases 

 of the claws. In flies, some bees, and many beetles, the 

 pulvillus is an adhesive organ, being furnished with 

 glandular hairs, which secrete a sticky substance, thus 

 enabling the insect to obtain a foothold upon smooth 

 surfaces, or to walk upside down. When the insect is 

 walking over a rough surface, and the claws provide 

 adequate foothold, the pad can be raised so as to escape 



