HERPYLLOBIUS ARCTICUS. 
397 
forms (Text-fig. 4). Directly beneath the hypodermis are a 
number of eggs (o. v.) lying in blind diverticula3 of the 
oviducts (o. d.) ; about the centre of the animal these con- 
verge into a single canal, which almost immediately divides 
again into the two glandular ducts {gl. d.) mentioned before, 
which run forward for a little way and then bend sharply back 
on themselves, so that each appears double in a considerable 
number of sections. Midway between these two tubes is a 
hollow sphere {m. v.) partially filled with a mass of tissue, frayed 
out at the edges into what, under an oil-immersion lens, looks 
remarkably like spermatozoa, and I have thought that this 
was a single sperrnatheca, such as is found in some Copepods. 
Such an interpretation is at variance with Jensen’s statement 
that large spermatophores are found in the male and fixed 
by means of a cement to the upper end of the long genital 
aperture of the female (see his figure, (6), Tab. ii, fig. 11a, 
his.), and I give it with reserve. 
At the lower end of this median vesicle there is, at either 
side, a tube with swollen lips, which leads outwards to 
another vesicle {1. v.), which is smaller than the median one, 
surrounded by thick walls, and apparently empty. Into each 
of the ducts, from the median to the lateral vesicles, there 
opens the glandular oviduct, and from it there runs posteriorlv 
another duct [g.d.), which opens to the exterior by a long 
slit, the genital aperture [g. o.) at the end of each of the 
chitinous bosses; these openings naturally only show when 
no egg-sacs are present. 
Even in the sections there was no trace of any canal 
running down the stalk. 
(b) Stalk and Root System. — As mentioned above, the 
skin of the external portion may be traced down the stalk to 
the chitinous hold-fast ; this has a serrated edge to which are 
attached strands of muscle-fibres (PI. 22, fig. Down 
the liimen of the stalk the tissues of the two parts of the 
copepod may be seen in direct communication, whilst the 
lacunar system of the roots may also be shown to communi- 
cate with certain spaces in the external portion, as noted before. 
