The Nervous System and the Senses 



163 



mit stimuli from the sense organs and some to carry stimuli 

 from the nervous system to the various organs of the body. 

 The nerve. fibers there- 

 fore are often compared 

 with wires used in con- 

 ducting electric energy 

 from place to place. 



In an hypothetical 

 generalized insect em- 

 bryo we should doubt- 

 less find a ganglion for 

 each segment of the 

 body, probably twenty 

 in all, but the ganglia 

 of the bee larva are 

 modified from the primi- 

 tive condition and in 

 the adult still further 

 specialization is ob- 

 served, by the fusion 

 of various ganglia. 



The brain (Fig. 85), 

 situated above the CBSoph- 

 agus, consists of three 

 consecutive ganglia, rec- 

 ognizable in the embryo, 

 but completely fused and 

 not readily recognizable 

 in the adult. From the 

 brain, two short connec- 

 tives (circum-oesopha- 

 geal) pass one • on either side of the oesophagus to the 

 suboesophageal ganglion (SceGng) also located in the 

 head. Continuous with the brain are the optic lobes (Opl) 

 forming the nervous connection with the large compound 

 eyes (E), and from the brain are nerves to the antennae 

 (AntNv) and also to the frontal ganglion (FtGng), from 



Fig. 



84. — Nervous system of worker, 

 dorsal view. 



