210 
W. A. HASWELL. 
ments, and finally a wider intestine running through the tail 
region and terminating in the anus at its posterior end on 
the dorsal side. The wall of the canal consists throughout 
of a single layer of comparatively large cells ciliated internally 
and a thin investment of the splanchnic coelenchyme, already 
referred to. Here and there is a cell which responds much 
more intensely than the rest to staining agents, and which 
may perhaps be differentiated as a secretory cell. 
Connected with the oesophagus are a pair of glands (figs. 2-5, 
gl. c.), not hitherto noticed which from their position may be 
termed the cervical glands. These are situated in the neck- 
segment at the sides of the oesophagus in the interval between 
the jaws in front and the intestine behind. In the living 
animal they appear as somewhat conspicuous objects owing 
to their greenish colour, but a very slight pressure causes 
them to become broken up, when the green matter becomes 
diffused through the space (coelom of neck segment) bounded 
by transverse septa in front and behind. Each gland is 
triangular in outline when looked at from above or below, 
one angle being internal and the other two external. The 
internal angle is in close apposition with the narrowest part 
of the oesophagus, where it passes into the intestine. In 
section the gland appears very finely fibrillated, not showing 
any trace of division into cells, with only a small number of 
nuclei placed at wide intervals. In one series of sections the 
gland appears to be unicellular with a single large nucleus, 
larger than any others that occur in the head-region, with a 
definite spherical nucleolus ; any other nuclei towards the 
periphery belonging to other elements. In other series this 
point is not so distinct. The two glands are closely applied 
together below the oesophagus, separated by a very fine 
median vertical fissure. Closely applied to their ventral 
surfaces are the transverse parts of the first or cephalic pair 
of nephridia, and between this surface and the ventral body- 
wall is a distinct space — the coelom of the neck-segment 
(fig. 1, ce. c.). 
Comparison of series shows that these glands are essentially 
