NERVOUS SYSTEM OF INSECTS. 



319 



the antennal nerves (Fig. 276, af). The simple brain of the 

 locust may be compared with the more complicated brain of 

 an ant, as seen in Fig. 279. 



The infra-oesophageal ganglion (Fig. 278, if), as its name 

 implies, lies under the oesophagus at the base of the head, un- 



Figi 879. —Eight half of an ant's-hrain: M(7,infra-ce6ophageaI ganglion; (?r, hrain; 

 C, central connective portions ; W, semi-circular Ijortles of the small-celled portion 

 or tiie brain lyin_' nuxt to the basal portion of the brain, from which the nerves to the 

 fimple eyes {au) arise ; Au^ optic lobes ; An. anteunal lobes {the bodies appearing 

 like cells are rounded massi'S of the network of the substance of the cord ; r. cellu- 

 lar cortical substance of the brain ; ko, twofold body of the commissure connecting 

 the brain wiih the iufra-cesophageal ganglion. — After Leydig, from Graber. 



der a bridge of chitine, and directly behind the tongue. It ia 

 connected with the supra-cesophageal ganglion by two com- 

 missures passing up each side of the oesophagus. From the 

 ander side of the infra-oesophageal ganglion arise three 

 pairs of nerves, which are distributed to the mandibles. 



