NERVOUS SYSTEM OE INSEOTS. 



319 



the antennal nerves (Fig. 276, at). 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. 378, if), as its name 

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



Fig; 279.— Eight lialf of an ant's-brain: Mff.infra-ceeopliageal ganglion; (?r, brain; 

 C, central connective portions ; W, serai-circular bodiea of the small-celled portion 

 of tbe brain lyini; next to the basal portion of the brain, from which the nerves to the 

 simple eyes (aw) arise ; Au^ optic lobes ; An.^ antennal lobes (tbe bodies appearing 

 like cells are rounded masses of the network of the substance ol' the cord ; r, cellu- 

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

 the brain wi:h the infra-cesophageal ganglion. — After Leydig, from Graber. 



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

 connected with the supra-cesophageal ganglion by two com- 

 missures passing up each side of the (Esophagus. From the 

 under side of the infra-oesophageal ganglion arise three 

 pairs of nerves, which are distributed to the mandibles. 



