PROSTATE GLANDS OF THE EARTHWORMS OF THE FAMILY MEGASCOLECIDAE. 441 
of the cell; the nucleus appears to disintegrate by becoming smaller, by solution 
of the chromatin to form a homogeneous staining mass, and by disappearance of 
the nuclear membrane. 
The most distinct granules stain with eosin ; and these occur sometimes in 
fairly definite aggregates. The rest of the glandular mass — its basis, after the 
abstraction of the nuclei, eosin-stainingj granules, and fibrillar differentiations — is 
5 .00 J 
indistinctly granular or amorphous. 
Neighbouring lobules often fuse indistinguishably in parts of their contour ; 
but often there is a distinct cleft — in sections appearing as a channel — between 
adjacent lobules. Where capillaries are present between the lobules there may be 
also a few fine fibrils of connective tissue ; but for the most part the channels 
between the lobules are empty, and the boundary of the lobule is merely the limit 
of the glandular matter. 
A capsule on the outer surface of the gland is seen in places, e.g. sometimes 
bridging the angle between contiguous lobules ; it consists of connective tissue 
with oval nuclei. The capsule may be traceable from such a point over neigh- 
bouring cells as a thin membrane, with here and there flattened nuclei. Sometimes 
the membrane, of extreme tenuity, seems to fuse with the surface of the cells and 
so to cease to exist. In some places there is no membrane, nor even a sharply 
limited cell-edge ; the granular matter forms the rather indefinite surface of the gland. 
In some cases where flattened nuclei are present on the surface of the gland they 
do not belong to a separate membrane, but to the granular matter underneath. 
There is thus every gradation between a separate capsule and none. A feasible 
explanation seems to be that capsule and gland are parts of the same tissue, 
developed from the same basis, as in the pharyngeal glands (cf Stephenson, 6). 
Similarly with the strands of connective tissue that attach the gland to the 
body-wall. There is no definite demarcation between strand and gland ; where 
the strand is attached to the gland it may be, for example, continued on one side 
over the gland for some distance as a distinct membrane with flattened nuclei ; 
further on these flattened nuclei become the superficial nuclei of the glandular 
substance ; ultimately they cease to be distinguishable from the ordinary nuclei 
of the mass ; on the other side of the attachment of the strand this condition 
may be attained immediately. 
In a few places the margin of the gland stains more deeply ; and here discrete 
cells with well-defined margins are present (fig. 3), the protoplasm of which stains 
sometimes equably and deeply, obscuring the nucleus, at other times unequally, 
the cell-body including a mass of deeply staining material — a condition which 
recalls the “ chromophil cells ” in the pharyngeal glands (Stephenson, 6). The 
nucleus can usually be made out as relatively large, spherical, with a large central 
aggregation of chromatin but no scattered granules. The shape and size of these 
cells are quite irregular; perhaps, a length of 11 to 14p. and a breadth of half 
