A STUDY OF THE GRASSHOPPER 17 



legs is attached to this segment. Between the forelegs there 

 is, on many species of grasshoppers, a short, blunt tubercle. 

 The second and third segments, the mesothorax and the 

 metathorax, are immovably fused, but their borders are indicated 

 by well-marked sutures. There is also on the side of each 

 segment a suture near the middle which divides the sides of the 

 segments into two sclerites. The mesothorax bears the second 

 pair of legs, which are similar to the first pair, and the first 

 pair of wings. The metathorax bears the large, third pair of 

 legs and the second pair of wings. 



Each leg is composed of several successive parts or segments. 

 The segment nearest the body is sub-globular and is called the 

 coxa; the second segment is smaller than the coxa and is called 

 the trochanter; the third, the largest, is the femur; the fourth, 

 the tibia, is long and slender; the three short segments beyond 

 the tibia are called the tar sal segments. The terminal segment, 

 which is longer and more slender than the others, bears a pair 

 of claws, between which is a little pad, the pulmllus. The 

 tibiae are armed with small spines, and the femora of the last 

 pair of legs are enormously developed, enabling the insect to 

 leap some distance. Just above the base of each of the middle 

 pair of legs is a small, slit-like opening, or spiracle, guarded by 

 two fleshy lips. These spiracles are the external openings of a 

 set of fine tubes forming the respiratory system, which as we 

 shall see, carries air to all parts of the body. 



The front wings are long, narrow and parchment-like, with 

 branched and unbranched longitudinal veins and many short 

 cross-veins. The hind wings are triangular in outline, mem- 

 branous, and when at rest are folded like a fan. Some of the 

 veins at the base of each pair of wings are thickened and raised 

 or depressed in such a way that they set the wings to vibrating 

 rapidly when they are rubbed together. This produces the 

 crackling sound sometimes heard when grasshoppers are flying. 

 A somewhat similar sound is produced when the insect, at 

 rest, rubs the roughened inner surface of the hind femora 

 against the outer pair of wings. 



Abdomen. The first segment of the abdomen has its upper, 

 or dorsal, and lower, or ventral, parts widely separated by the 



