THE STRUCTURE OF INSECTS. 



15 



ganglion by two commissures passing up eacli side of the 

 oesophagus. From the under side of the infra-oosophageal 



AG1-* 



C 



FIG 9 A, nervous system of ant, Formica ruf a; B, Melolontha; C, flesh-fly, 

 Sarcophaga carnaria; Stg, frontal ganglion of the sympathetic nerve; oSg, 

 brain- uSg. infra-oesophageal ganglion; BO, thoracic ganglia; AG, abdominal 

 ganglia : the dotted lilies passing through homologous ganglia. From Ju- 

 deich and Nitsche. 



FIG. 10.-Supra-oesophageal ganglion and visceral (or sympathetic) nervous 

 system of the silk-worm moth (Bombyx mori). gs, supra-cesophageal ganglion 

 ("brain"); a, antennary nerve; o, optic nerve; ?-, azygos trunk of the visceral 

 nervous system; r', its roots arising from the supra O3sophageal ganglion; 

 s. paired nerve with its ganglionic enlargements, s' s". After Brandt, from 

 (jegenbaur. 



