422 THOS. H. MONTGOMERY jr., 
the nerve could not be determined. These hypodermal cells are thus 
probably peripheral sensory elements, even though they also are the 
producers of the cuticle; it is to be noted that the cuticle over these 
cells is particularly thin, so that the whole surface beneath this thin 
cuticula might be especially adapted for touch sensations. The distal 
fibres of these cells cannot (by staining be differentiated from the 
fibres of the chromophilic cells placed within the central nervous 
system. 2) Deep-staining fibres (Chl.C Fig. 35) of chromophilic cells 
placed within the cephalic ganglion and cephalic nerves. These appear 
to end between the hypodermal cells. The relations of these elements 
may best be seen on the Fig. 35. 
The nervous connections in the paired and unpaired septa which 
connect the ventral surface of the cephalic ganglion with the hypo- 
dermis, appear to be the same as in the region just described. 
It is to be noted that the hypodermis of the head region does 
not possess the small, irregular, deep-staining sensory elements which 
are to be found in the trunk region. 
In the head region a certain number of the fibres of the chromo- 
philic cells course between the parenchym cells (L. Par Fig. 35). The 
cephalic nerves when not in connection with the hypodermis, are 
bounded in part (especially dorsally and medially) by the capsule cells 
of the eye, in part by small parenchym cells. 
I. The peripheral Nervous System at the posterior End 
of the Female. 
The cloacal ganglion in the female (Fig. 36, Pl. 39; Fig. 72, 
Pl. 41) is in immediate contact with the cloacal epithelium (Cl. Epi), 
and processes of these elongated and bent cloacal cells (Cl. Epi Fig. 36, 
Pl. 39) penetrate for some distance into the dorsal surface of the 
ganglion, and even partially invest the more dorsal chromophobic 
nerve cells (Chb.C). Most of the chromophilic nerve fibres which 
have a vertical course in the ganglion pass into and end in the cloacal 
epithelium, lying just within the basement membrane of the latter, 
and some of these may be traced up the sides of the cloaca for some 
distance; but terminal plexuses of these fibres within the cloacal wall 
could not be determined. In one very clear case (Fig. 76, Pl. 42) it 
could be determined that a chromophobic fibre (Chb. F) accompanied 
a chromophilic one (Chl. F) into the cloacal wall; in this case the 
chromophobic fibre could be traced to the point where it bent at 
right angles to form a cloacal nerve (071. N), while the chromophilic 
