PROSTATE GLANDS OF THE EARTHWORMS OF THE FAMILY MEGASCOLECIDH3. 443 
Where separate cells occur in some places near the periphery of the gland, there 
are no indications of long necks connecting them with the ductule (fig. 3). 
However, in view of the fact that in the adult, separate cells for the most part 
do not exist, there can be no doubt that the secretion from the peripheral parts of 
the glandular mass filters through the glandular tissue to the ductule. 
The Ducts outside the Gland. — On escaping from the gland the duct — the 
united ducts of the lobules- — acquires its muscular coat. There is no general 
peritoneal coat over the duct — for the most part the muscular tissue is on 
the surface. 
In a dissection, the vasa deferentia, leading from the two male funnels of each 
side in segments x and xi respectively, appear to unite in segment xii, and an 
apparently single duct on each side travels back to the prostate. The two vasa 
deferentia of each side are, however, though bound up together, still separate up 
to their junction with the main prostatic duct where this emerges from the gland. 
Here the vasa deferentia penetrate the muscular coat of the prostatic duct and 
approach the lumen ; but, as was first pointed out to us by Dr Baini Prashad, 
formerly Assistant Professor in this Department, they can be followed along, still 
double, in this position throughout the whole length of the prostatic duct, only 
actually entering the lumen of the latter close to its termination at the surface 
of the body. 
(3) Structure of Supernumerary Prostates without Ducts (fig. 4). 
These organs were found to be compact masses of closely fitting lobules which 
were not always distinctly delimited from each other. 
On the whole, the cells are here more distinct than in the ordinary gland, and 
their surface may be defined by a fine deeply staining lamella, or perhaps a fibrillar 
differentiation ; at other times the territories of neighbouring nuclei are not delimited 
at all. The fibrillar differentiations of the glandular mass appear here to delimit 
cell territories rather than to wander indiscriminately through the mass. 
The cells, where they are distinct, are irregular in shape, and measurements are 
difficult ; they may be about 20 p. in diameter ; or an elongated cell may measure 
35 by 18 /r. The protoplasmic substance is either evenly granular, or apparently 
disintegrating, in such a way that there is an area which is only loosely filled with 
granular matter or is partly empty. Of neighbouring cell territories some may thus 
appear moderately homogeneous and rather darkly staining ; others almost empty, 
with only a small quantity of granular matter inside. A section has thus a curiously 
uneven appearance. 
The nuclei are large, roundly ovoid, 7 by 5 or 6 y in diameter, with scattered 
granules and one larger chromatic grain ; the large grain may be absent, but this 
is exceptional. There are also intracellular fibrillar differentiations, as well as those 
which appear to mark out cell boundaries. 
TRANS. ROY. SOC. EDIN., VOL. LII, PART II (NO. 16). 
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