226 Annals Entomological Society of America [Vol. IV, 



nerve fibers, running along the outer side of the connective and 

 for the most part ending in the basal portion of the ganglion next 

 above, near or across the middle line. A similar tract to this 

 has been described coming from the two most lateral trunks 

 in the last ganglion. 



These fibers which enter from cephalic lateral trunks seem 

 to stain among the first and in the case of some other insects 

 were found to come from bipolar sensory cells at the periphery, 

 and I still think that they are to some extent sensory, but these 

 tracts which have no communication with the cells of the gan- 

 glia with which they are connected are not all of the sensory 

 fibers of each nerve center, for the ventral branches have many 

 sensory fibers and these do not follow exactly the same path, 

 and in the case of the first seven abdominal ganglia many of 

 the fibers could be traced from the branch 2, which so far as 

 could be determined was a decidedly motor trunk. 



Fibers other than those coming from cells on the opposite 

 side to run into the branches as motor axones, are directly 

 supplied by cells on the same side, long branches from certain 

 cells run into the various motor trunks while the other termina- 

 tions are in the "punktsubstanz." 



Fibers from the periphery or from sensory cells enter the 

 ganglion from both main trunks and are of the following 

 groups: (a) Those ending within the ganglion to which the 

 trunks are connected, the exact termination of these T could not 

 make out, but some at least ended near the central part of the 

 ganglion, although very often arborizations of the terminations 

 could be traced both on the same side and on the opposite side. 

 Fibers entering straight from below in the last abdominal broke 

 up into branches near the middle line with arborizations in the 

 central margin of the ganglion. 



(b) Those passing from one ganglion to the next without 

 sending branches to the center to which the nerve trunks are 

 connected, some of these fibers may run past one or more 

 ganglion, but the most of them form a definite tract from the 

 periphery by way of lateral trunks, running on the outside of 

 the connectives, and turning sharply in towards the middle 

 line in the caudal portion of the central mass of fibers, to end 

 here or a little higher up, or to cross over and end in the "punkt- 

 substanz" of the opposite side not far from the middle line. 



