i 3 4 ECONOMIC ZOOLOGY AND ENTOMOLOGY 



legs is the rule rather than the exception. The bee's legs are 

 well fitted for walking, but they are also modified, the hinder 

 ones especially, for the performance of other functions. The 

 fore legs carry a number of branched hairs and curved bristles 

 for collecting pollen. They also have a curious little combina- 

 tion of structures called an antenna cleaner composed of a 

 rounded indentation lined with a row of short spines and nearly 

 closed by a large movable spine. The middle legs have also 

 pollen-gathering hairs and a curved spine which is used to pry 

 the pollen from the hindmost pair of legs. The hindmost 

 legs are most modified of all. They have a so-called "pollen 

 basket," or concave outer surface margined with curved bris- 

 tles; "pollen combs" composed of transverse rows of short 

 strong hairs; and, finally, a structure called the "wax-pincers," 

 being the two opposed edges of two joints of the leg, one lined 

 with spines, the other smooth. This structure, according 

 to Casteel, has nothing to do with cutting wax, but aids in 

 the gathering of pollen. 



The separately articulated parts or joints of each leg have 

 been given special names. Beginning with the one which 

 articulates with the body, called the coxa, the others are the 

 trochanter, a very small one, the femur, which is the largest, 

 the tibia, which is next in size to the femur, and finally the 

 tarsal segments, which, in the bee, are five in number. The last 

 or terminal one bears a pair of claws and a little pad called the 

 piilvillus, lying between the claws. These tarsal segments 

 vary from one to five in different insects. 



The legs of insects show great variety in structure and use. 

 Aquatic insects have one or more pairs of the legs modified to 

 be swimming organs; subterranean insects have digging legs; 

 leaping insects have the hindmost pair usually very large and 

 long. Some predaceous insects have the forelegs modified 

 to be grasping or lacerating organs. In fact only those in- 

 sects which use their legs exclusively for walking and running 

 have them in a condition which might be called unmodified. 

 In such insects they are usually long and slender with the seg- 

 ments more or less cylindrical in shape. 



The last tarsal segments of the different legs can be called the 



