444 PROFESSOR J. STEPHENSON AND PROFESSOR HARU RAM ON THE 
A marked difference from the ordinary gland is that the above-described is the 
only type of nucleus present. In the disintegrating cells the nucleus appears to 
disintegrate by first becoming clearer, keeping, however, the central chromatic grain, 
and then breaking up by solution of the nuclear membrane. 
Ductules are numerous, and are often seen between the lobules as well as in 
their centres ; the smallest have a diameter of 17 g, the larger of 34 /r. Here 
also an intralobular ductule, when followed out to its beginning, seems to lose 
itself amongst the gland cells in the centre of the lobule. And, as before, it 
seems certain that here also the majority of the cells cannot be in connection with 
the ductule. 
A smaller (and so perhaps younger) gland from the same worm shows a similar 
structure, except that there is less disintegration of the cells. The whole is more 
homogeneous, and there are fewer of the comparatively empty cells. 
The interesting feature is that previously mentioned in the Introduction — the 
entire absence of a duct leading to the exterior. The probability, therefore, is that 
the glandular mass was developed in situ, i.e. from mesoblastic tissues, and not from 
an invagination of the epiblast. 
(4) The Prostate in the Young Pheretima (fig. 5). 
In a small worm, in which the male pores were visible but the clitellum had not 
formed, the prostate was a small mass without distinct lobulation, staining deeply 
owing to the crowded nuclei in its substance. The nuclei, or “ cells,” are arranged 
so as to form — 
(a) Aggregates in which a lumen is visible in the middle of a dense crowd of 
nuclei, between which there are no cell-divisions the protoplasm is hyaline, tending 
to granular ; the chromatin of the nuclei is granular and scattered. These tubes 
are evidently in process of differentiation in a common mass of nucleated protoplasm ; 
their size varies — some are relatively large. 
( b ) More or less circular aggregates, without lumen. These resemble the last 
aggregates, except in the absence of a lumen. 
(c) Small irregular aggregates with no definite arrangement. The nuclei are 
disproportionately numerous relatively to the amount of protoplasm. 
( 1 d ) A number of nuclei, some staining evenly and densely, with scarcely any 
protoplasm. These are found in the interspaces between the aggregates of 
types (a), ( b ), and (c). 
There are no cell outlines in any part of the developing gland ; the whole is a 
continuous mass, with certain definite arrangements of nuclei in certain parts, and 
a few cavities, or spaces : (i) of regular form, in the centre of the aggregations of 
nuclei ; (ii) or irregular tracts, where the tissue is looser, foreshadowing apparently 
a division into lobules. 
There is no gland capsule — nothing that goes beyond the flattening of the super- 
