NERVOUS SYSTEM. 



197 



before them on the columns, as seen in the annexed figure 

 by Lyonet, of the three last pairs of ganglia and of the nerves 

 which come from them, in the larva of the cossus ligniperda 

 (Fig. 84. A.) The upper portion (a,) of the columns is seen 

 to give off the inter-ganglionic nerves (d, c,) which Lyonet 

 showed to be distributed on the respiratory organs after 

 receiving a small connecting branch from the first pair of 





FIG. 84. 



the next succeeding ganglionic or mixed nerves (11. c } c.) 

 This arrangement of the motor and ganglionic nerves is 

 represented at each inter-ganglionic space along the columns. 

 It was likewise shown by Lyonet that these motor nerves 

 (13. 6,) proceeding to the lateral muscles and respiratory or- 

 gans, come from a tract occupying always the upper surface 

 of the columns, and distinctly passing over the upper surface 

 of at least the last pair of ganglia. 



