\1\ \\D I'll 



brain cannot i;o to its fund, though it IS able i <-d in 



contact with the end-organs of taste, as th< 

 of the palpi; furthermore, it walks <.r llie> in an 

 erratic mamuT. indii atin^ a lack of < o urdina 

 tion of muscular action. 



The SUbcesophageal ganglion controls tin- 

 month parts. CO ordinatin^ their movement 9 as ^ 

 well as some of the bodily movements. 



The thoracic ganglia govern the appendages 

 of their respective segments. These ganglia 

 and those of the abdomen are to a great extent 

 independent of brain control, each of these 

 ganglia being an individual motor center for 

 its particular segment. Thus decapitated in- 

 sects are still able to breathe, walk or fly, and 

 often retain for several days some power of 

 movement. 



In regard to the sympathetic system, it 

 has been shown experimentally that the fron- 

 tal ganglion controls the swallowing movements 

 and exerts through the stomatogastric nerve 

 a regulative action upon digestion. The dor- 

 sal jsympathetic system controls the dorsal FIG. n 6. Sympathetic nerv- 

 vessel and the salivary glands, while the s system O f an insect, 



' diagrammatically represented. 



Ventral Sympathetic System is Concerned with a, antennal nerve; b, brain; /, 

 .1 i -I frontal ganglion; /, /, paired 



the spiracular muscles. lateral gang i ia; m , ner ves to 



upper mouth parts; o, op- 



5. SENSE ORGANS tic nerve; r, recurrent 



nerve; s, nerve to salivary 



For the reception of sensory impressions glands; st, stomachic ganglion. 



r i u i vi After KOLBE. 



from the external world, the armor-like integu- 

 ment of insects is modified in a great variety of ways. Though sense 



FIG. 1 1 7. Transverse section of an abdominal ganglion of a caterpillar. /. nerve fibers; g, 

 ganglion cells; n, nerve sheath; p, Punktsubstanz. 



