OF INSECTS. 225 



The nervous system consists of a series of swellings, ganglions, 

 united by threads, which extend from the head to the posterior 

 end of the body, along its lower median line. In the head is a 

 double ganglion, (sg,) the so-called brain, which lies across the 

 upper side of the throat (gl) just behind the mouth. From the 

 " brain " a thread passes around on each side of the throat to 

 the lower side, and unites with the first ganglion (g) of the tho- 

 rax. This constitutes the nervous collar, (c,) and serves to unite 

 that part of the system above the intestinal tract to that below 

 it. The anterior (fig. 131, g) of the thorax-ganglions is scarcely 

 separate from the succeeding one, and the latter (g 1 ) is the result 

 of the intimate fusion of the second and third. Their consoli- 

 dation corresponds to the degree of concentration that the rings 

 of the thorax attain to ; there being in the latter an imperfect 

 separation between the first and second joints. The abdominal 

 ganglionic chain (n) is single, and passes backwards in a direct 

 line from the posterior double thoracic ganglion, with a ganglion 

 (g" 2 5 eT 3 > f*) a * nearly every joint. From these ganglions minute 

 nerves pass off, right and left, above them and on each side to 

 the various organs ; and likewise similar nerves, arising from 

 the " brain," supply the feelers, expand in the eyes, and branch 

 over the upper side of the throat and stomach. 



The reproductive system lies in the posterior part of the abdo- 

 men. It consists of a pair of bunches (ov) of wavy tubes, 

 which converge into one channel, oviduct, (d,) on each side. The 

 two oviducts pass down each side of the intestine to a point 

 just in front of its termination, where they unite in one com- 

 mon outlet (o) on the middle, inferior line of the body. The 

 eggs are generated in the bunches of tubules, ovaries, (ov) ; and 

 when ripe they pass into the oviducts, and thence through the 

 common channel (o) to the place of deposit. 



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