240 Annals Entomological Society of America [Vol. IV, 



Two other sorts may be given although no complete fibers were 

 traced through such a course; 



(b) It seems probable from the specimens that fibers cross to 

 the opposite side in the commissure and run over to the oppo- 

 site side of the ganglion: 



(c) Probably some fibers cross in the commissure and run 

 back to the brain. 



Fibers running straight through the ganglion from above 

 and from below were not traced but it is very possible that such 

 are present as in other ganglia. 



THE NERVE TRUNKS. 



The mandibular branch sends its fibers into the cephalic 

 dorsal border of the " punktsubstanz." Some of its fibers seem to 

 end here, others pass in deeper. 



The maxillary sends its fibers into the very center of the 

 upper half of the ganglion and here some of them seem to end or 

 cannot be traced farther in surface views. This is true of the 

 more cephalic branch of the maxillary in part at least, while the 

 rest of. the fibers of this and those of the caudal branch are 

 traced in laterally a little farther down. 



The fibers of the labial nerve; some of them run in deeply 

 about where the branch enters the ganglion, others go down 

 farther and may be traced as far as the place where those of the 

 ventral nerve trunk enter the mid-lateral portion of the central 

 fibrous mass. 



The salivary nerve fibers run in and can be traced to near 

 the point where the ventral nerves were. 



The small gustatory nerves run some distance down into the 

 ganglion from the point where they take their exit and a motor 

 nerve cell was found sending out its axon directly into this 

 tract. 



SUBESOPHAGEAL GANGLION STUDIED IN SECTION, BEGINNING AT 

 THE CAUDAL END. 



The connectives which run up to the subesophageal ganglion 

 are much like the others described. As the caudal portion of 

 the ganglion is reached these two longitudinal tracts of fibers 

 become fused although they may be distinguished from each 

 other. A group of nerve cells appears on the lateral sides, and 

 a group of large ones on the median side dorsally, some of these 



