PHYSIOLOGY OF THE BEE. 83 



the separation of their filaments to inclose the gullet 

 together with a more plainly-defined distance be- 

 tween the cords which run parallel through the rest 

 of the body. 



FIG. 24. NERVOUS SYSTEM OF PERFECT INSECT. 



In the perfect insect we observe some decided 

 modifications to have taken place. The head por- 

 tions have grown proportionally larger, and show a 

 loop for the passage of the oesophagus, while two 

 large ganglia in the thorax indicate the seat of im- 

 pressions and impulses connected with the organs of 

 motion wings and legs which had no existence in 



G 2 



