PHYSIOLOGY OF INSECTS. 99 



antennae or feelers, two eyes, and a mouth : the 

 head is very distinct from the following segments, 

 and is generally so articulated to the second seg- 

 ment, as to possess freedom of motion in every 

 direction. 



322. The second segment (prothorax) is the 

 one which is so very large and convex in the 

 common chafer, and which appears to receive the 

 head into an excavation or cup : in a locust, or a 

 cricket, it is equally large ; but in a butterfly, fly, 

 or bee, it is exceeding narrow, and scarcely per- 

 ceptible. 



323. The prothorax bears a pair of legs, which 

 are called fore legs (jtropedes) ; these legs are 

 so articulated to the prothorax, as to allow perfect 

 freedom to their movements. 



321. The third segment (mesothorax) is the 

 large convex part so prominent in butterflies, 

 bees, and flies ; it is a narrow segment in beetles, 

 crickets, &c : it is so articulated with the pro- 

 thorax, as to allow that segment less freedom 

 of motion than is possessed by the head. 



325. The mesothorax bears two wings, one of 

 which is attached to each side of it ; these are 

 called fore wings {proalce) : and two legs attached 

 to its inferior surface ; these are called middle legs 

 (mesopedes) ; they possess equal freedom with 

 those of the prothorax. 



326. The fourth segment (metathorax) is small 

 in butterflies, flies, and bees, but large in beetles, 



II 2 



