222 Annals Entomological Society of America [Vol. IV, 



trunk, but run directly up to the next ganglion by the way of 

 the connectives, in a tract which from its other connections in 

 other species and in this form, and from its staining reactions, 

 I took to be sensory. Branch 3 is long, it runs up to the dorsal 

 side of the animal and is without doubt mixed motor and 

 sensory, containing fibers which supply dorsal muscles and 

 fibers which come from the hypodermis. Branch 1 runs into 

 the lateral appendage and seems to be sensory, for the most 

 part at least. Besides these, there are two minute branches. 



1 and 5, running out to the trachea, according to Hammar, '08. 



The ventral trunk runs caudally and ventrally, branches 1, 



2 and 3 run to more and more caudal portions of the ventral 

 side of the animal and seem to be entirely sensory, branch 3 

 runs to some extent also into the lateral appendage, while 

 branch 4 runs into the tracheal gill and was the only one traced 

 into it. So this whole ventral trunk seems to be for the most 

 part sensory. 



The eighth abdominal ganglion seems to be made up of at 

 least two centers fused, there are four main trunks entering it 

 on each side below and all of these so far as could be determined 

 are both motor and sensor}'. Trunk (a) is most lateral, (b) 

 a ventral trunk corresponding to the ventral one of other ab- 

 dominal ganglia, (d) a more median one supplying lower dorsal 

 and ventral portions of the body and (c) median, with a large 

 branch which runs back up the intestine. 



NERVE CELLS. 



(Fig. 5.) 

 The nerve cells of the periphery have already been figured 

 in an earlier article, Hilton '02. The functional cells of the 

 ganglia both thoracic and abdominal appear to be much of the 

 same type in methylene blue preparations, uni- or bipolar nerve 

 cells, one of the processes or branches of which may run out 

 quite a long distance before the}' break up into a number of 

 terminations, the other portion usually breaks tip into branches 

 near the cell body. Indications of multipolar cells were seen 

 in some specimens but with these usually all of the processes 

 but one were very small and hard to trace very far. In addi- 

 tion to the functional neurones of both large and small size, 

 there were in all of the ganglia, numerous neuroblasts, or smal- 

 ler cells with slight protoplasm about the nucleus, and neurog- 

 lia networks. 



