EDEN 
The nucleus is spherical or ovoid, and occupies from one-half to 
two-thirds the body of the cell. From a point upon the side of the 
cell, slightly removed from the base, extends the nerve fibre. The 
body of the cell passes, by a more or less abrupt shoolder, into the 
neck, which reaches the cuticle and penetrates into that layer, in some 
cases a distance of one-third its thickness. The diameter of the neck 
is very constant in different cells (8 « to 4 u). One stout hair, or 
bristle, 4 « to 7 u in length is borne upon the squarly truncated neck. 
In Gouai preparations the precipitate upon the cuticle may partially 
or completely hide these hairs. 
Fig. 5. Groups of sensory cells and sense organs. 1 and 2, Groups of cells from 
epidermis of the posterior end. 3. Group from the fourth body segment, 4. Section, 
7 u thick, thro a sense organ upon the ventral surface of the prostomium, 1, 2 and 3 
from silver preparations. 4 from vom RATH preparation, 
The isolated sense cells vary from this general type in several 
ways. Near the extremities where the epidermis, owing to the greater 
height of the cells, is thicker than over other portions of the body, 
the sense cells are also higher, and become flask or even spindle 
shaped (Fig. 3, Nos. 3 and 4), rather than thick and jug shaped, as in 
regions where the epidermis is thinner. In such elongated sense cells, 
the distinction between neck and body is less evident. In a few cells, 
perhaps one in ten, thick blunt processes extend from the base (Fig. 4, 
No. 6). These processes are not over 2 w in length, and may occur 
as many as five from a single cell. Over the anterior extremity three 
to five hairs may be borne by one cell (Fig. 4, No. 7). These hairs 
are slightly more slender than the single hair borne by similar cells, 
but otherwise not different, either in length or in mode of origin from 
the neck of the cell. The place of origin of the nerve fibre may be 
at one of the lower corners (Fig. 4, No. 4), or, in the more spindle 
shaped cells, it may be a continuation of the tapering base (Fig. 3, 
Nos. 2, 3). In a few instances the nerve fibre seems to spring directly 
