The adult organisation of Paragordius varius. 4? 1 
H. The peripheral Nervous System of the Head. 
As has been described earlier, the fibrous tracts of the cephalic 
ganglion diverge and passing anteriorly as the cephalic nerves (Ceph. N 
Figs. 2, 3, 7, Pl. 37; Fig. 17, Pl. 38) end against the hypodermis. 
The nerve endings in this hypodermis and the character of its cells 
can be best determined on longitudinal sections of the head stained 
with iron-haematoxylin (Fig. 6, Pl. 37; Figs. 34, 35, Pl. 39). 
Anteriorly, laterally and ventrally the hypodermal cells are greatly 
elongated and are directed backwards (Hyp Figs. 1, 6, Pl. 37); certain 
of them form the anterior lining (E. Hyp) of the eye, and will be con- 
sidered with that organ; the others and their nervous connections 
concern us at present. 
In this hypodermis may be distinguished the following elements. 
1) The cuticular cells of the hypodermis (Figs. 34, 35, Pl. 39), the 
largest elements and the most numerous, which are here longer than 
in any other region of the body, and directed backward at an acute 
angle from the cuticula. For some distance behind the head this 
backwards-pointing of these cells is to be seen. The nuclei (Hyp. N) 
of these cells lie generally quite close to the cuticula, where the cell 
body has its greatest diameter; more distally (internally) the cell body 
attenuates, becoming flattened and terminating as a fibre; the cyto- 
plasm is quite vacuolar. 2) Smaller cells lying between the preceding, 
and generally with a deeper position within the hypodermis (Fig. 34). 
Their nuclei are also smaller and stain less deeply with iron-haemato- 
xylin; generally the cell appears spindle-shaped like a long fibre with 
a middle dilation containing the nucleus; though distinctly bipolar, 
there sometimes appears to be more than one process going out from 
either end of the cell. In some cases it could be determined that 
the cell extended completely from the outer to the inner surface of 
the hypodermis. 3) Small rounded cells (Chb.C.? Fig. 35) with a 
very faintly-staining nucleus, very few in number and lying between 
the other cells: these may be small chromophobic nerve cells. 4) Fibres 
(E. Cap.C Fig. 34) from the tissue of the eye capsule, which will be 
considered elsewhere. 
The nervous connections of these cells with the cephalic nerves 
are of several kinds (Fig. 35, Pl. 39). 1) The distal, fibrous termin- 
ations of the cuticular cells and those of the 2nd type of cells of 
the hypodermis are continued into the cephalic nerve (Ceph. N) of the 
corresponding side, though whether they course for any distance within 
