40 JOURNAL, OF ENTOMOLOGY AND ZOOLOGY 



tral tlinn that of the ])Ostanteniial mass of fells. T was unable to 

 detect any special lol)e of the brain connected with this nerve. 

 Branches from this trnnk run dorsally and ventrally. Closely 

 connected with this nerve on each side a little distance forward 

 from the base of the brain is a small g-an,<;iion with a few nerve 

 cells. These little centers I believe represent the paired vis- 

 ceral ganglia of other insects. A little cephalad of the level of 

 these small nerve centers and dorsal to the esophagus, between 

 the anteunal nerves there is a minute ganglion with a number of 

 little brandies. This I believe is tlie frontal. From it on each 

 side an arched nerve descends to connect with the two lateral 

 ganglia just where they meet the labial nerve. Other branches 

 go to the head region and one descends on the dorsal side of 

 the intestine for some distance. 



In order to determine the position of various parts of the 

 ganglia, there was made in blotting paper a model of the large 

 head centers and this, together with a graphic reconstruction 

 from a very perfect series of longitudinal sections, furnished 

 tlie basis for most of Figs. 1 and 2. 



Some General Conclusions 



(1) There are two large ganglia in the head, one for each 

 segment of the thorax and a fused mass of nervous tissue in the 

 upper alidcuuinal region. 



(2) The abdominal ganglion is clearly made up of several 

 centers fused together. 



(3) The supraesophageal ganglion has an antennal nerve on 

 each side. There is also a labral nerve of smaller size and a 

 connection on each side with the i)ostantennal sense cells. 



(4) The subesopbageal ganglion is joined by broad con- 

 nectives with the brain and by less broad connections with the 

 first thoracic ganglion. 



(5) There are three main nerves connected with the sub- 

 esophageal ganglion— the manlihnhir, maxillary and labial. 



(6) Connected with the brain are three small ganglia, the 

 frontal and two lateral visceral ganglia. The first of these is 

 very small. 



