i ;> i- 



XERVOUS SYSTEM. 



papilio brassicas. In the larva of that lepidopterous insect 

 (Fig. 83. A,) the columns are lengthened, the ganglia widely 

 separated, and nearly equal, with a large ring between the ce- 

 phalic (1,) and the first infra-oesophageal (2,) ganglia. The first 

 or cephalic ganglia (A. 1,) were observed by Lyonet to give 

 off eight pairs of nerves, which pass chiefly to the organs of 

 the senses, besides the two columns which connect them 



FIG. 83. 



with the second pair of ganglia (A. 2.) They give off, like- 

 wise,, filaments to the small lateral ganglia (A. b,) of the 

 head, and to the commencement of the sympathetic series of 

 ganglia (A. ,) as shown by Lyonet in the cossus. Between 

 all the succeeding pairs of ganglia a solitary branch is seen 

 coming off from each side of the motor column, which inter- 

 ganglionic nerves were shown bv Lyonet to be distributed 



