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PROFESSOR J. STEPHENSON AND PROFESSOR HARTJ RAM ON THE 
the gland, which thus appears to be the freely proliferating tip of a mass of 
mesoblastic cells. 
On passing back the tubes may become distinct from the general mass of cells, 
or, on the other hand, they may still appear continuous with the general mass. 
The nuclei are throughout deeply staining and homogeneous. 
A number of cells, or rather nuclei, on the surface of the gland are much 
flattened, and a transformation of the surface of the gland into connective tissue 
appears to be taking place in parts, especially on the outer side of the gland. 
Fine strands, continuous with the glandular mass, connect it with the body -wall. 
The lower part of the mass, the future muscular duct, shows no elongation 
or transverse arrangement of the nuclei ; continuous with the future gland above, 
it is continuous in the body-wall with the infiltration of connective tissue cells 
around it. 
The surface epithelium is already canalised to form the pore ; the cells around 
the pore are considerably higher than those over the general surface of the body ; 
the appearances do not point to any ingrowth or invagination of these cells. 
The whole prostatic mass, therefore — glandular epithelium, duct epithelium, 
muscular wall of duct, connective tissue connections of gland to parietes — appears 
to arise as a proliferation of indifferent, in origin mesoblastic, cells ; and the various 
parts of the adult gland are produced by differentiation of these. The portion of 
the duct epithelium which arises by invagination from the surface appears to be 
negligible. 
(6) Other Stages in the Development. 
A number of young specimens of Pheretima, and probably one of Lampito 
mauritii, belonging to an allied genus, were sectioned, and help to fill up the 
interval between the stages already described. Concerning them the following 
remarks will be sufficient. 
The appearances all indicate that the prostate begins as a proliferation of 
indifferent or connective tissue cells on and in the muscular layer beneath the 
peritoneum. There is no indication of the place where the mesodermal portion 
of the duct meets the invaginated epidermal portion, or even if there is any 
invaginated epidermal portion. 
The infiltration of the muscular layer of the parietes with connective tissue 
cells is seen ; in some cases the nuclei are accompanied by delicate fibrils. 
Followed to their commencement, the ducts melt away into the substance of 
the young gland ; but at some distance from their origin they become separate 
and distinct in the middle of the cells which surround them. The main duct 
inside the gland, in sections where it is cut along its length, appears as a long 
straight tube with lateral buds. 
The young gland has no proper capsule at any place. It is connected to the 
