24 



The Form of Insects 



and armed with formidable rows of strong spines. 

 The end of the leg is formed by a five-segmented 

 foot {tarsus), whereof the first segment is the longest, 

 and the third and fourth the shortest j the fifth 

 segment carries two claws (l). 



The legs undergo the greatest modification accord- 

 ing to their special functions in different insects (9, lo). 

 The front pair, which are the shortest in the cock- 

 roach, are greatly lengthened in certain beetles which 

 climb about on trees, and immensely widened in other 

 beetles which burrow underground, while in the "pray- 



FiG. 20. — Modification in the legs of Bees. A . Honey-bee {Apis) ; B. MeUpona ; 

 C. Bamhus. a.f. h. outer view of hind-leg ; b.g. i. inner view ; d. fore-leg ; 

 e. tip of middle shin with spur ; c. feathered hairs with pollen grains 

 From Riley, Insect Life, vol. 6 (U.S. Dept. Agr.). 



ing-insects " and water-scorpions, they are modified 

 into formidable pincer-like organs for seizing prey. 



In many Beetles a cavity in the front shin lined 

 with bristles serves as a "comb" for cleaning the 

 feelers, which can be drawn through it. In Bees a 

 still more perfect organ for the same purpose is formed 

 by a semi-circular nick near the upper end of the 

 first tarsal segment (164). The cavity is lined with 

 thickened hairs, and its open edge can be bounded 



