FISSION IN NEMERTINES. 29 
and then by a thick coat of longitudinal muscles. But the 
epithelium changes its character for a short space near its 
anterior end; the gland-cells, so conspicuous elsewhere, no 
longer catch the eye in section, if indeed they are present ; 
but the cells are long, narrow, with flat nuclei at the sides, and 
close to the free end there is a series of round nuclei arranged 
in a well-defined row. 
In longitudinal section this region occurs between 2 and 
3mm. from the anterior end; whether it corresponds to the 
blood-red tract on the proboscis, noticeable in the living worm, 
I am not certain. 
In all the Palzonemertini the parenchyma is but very 
feebly developed, but in the present worm, at any rate behind 
the middle of the body, it is practically absent. I can detect 
no space between the wall of the gut-muscle, and body-wall, 
i.e. between the inner circular muscles and the longitudinal 
muscles, except the longitudinal blood-vessel on each side and 
a nearly homogeneous tissue (y.) passing up from it to the inner 
wall of the intestine; this tissue resembles the ordinary con- 
nective tissue, which occurs in some sections in sheets quite 
like this little piece. This is all that represents the “ paren- 
chyma”’ posteriorly. 
There is one point in which this Carinella does not agree 
with Biirger’s statement as to the arrangement of the gonads. 
He states that in the Palzeonemertini there is usually more 
than a single pair of gonads in a transverse plane, so that a 
transverse section through this region would exhibit more than 
two gonads and ducts. ‘This is not the case with the present 
Carinella. The gonads are strictly paired; there is one, 
and only one, on each side,—each with its duct formed in the 
usual way. ach ovary when nearly ripe consists of three or 
four large ova, surrounded by a common membrane of flat 
cells, which is continuous with a heap of indifferent rounded 
cells on the outer side of the ripe cells (fig. 12). Amongst this 
mass of rounded cells one can distinguish one or more cells, 
still small, but distinctly larger than the rest, with a distinct 
germinal vesicle (ov.); these are evidently young ova. 
