In solipedes there are two prostates, situ ated by the side of the vesiculm; the cavities of these are large, and the parenchyma small in quantity ; they are covered by muscular fibres coming from the vesiculm and neck of the bladder ; their excretory ducts terminate by many orifices on either side of the ducts of the vesiculm.
The ruminants have also two prostates, precisely similar to the preceding. They are larger in the ram and bull, and are coinposed of distinct lobes, each containing small cells, which communicate with a large central ca vity ; this opens by a duct in a large lacuna of the veru montanum, either internal to or be hind the vas deferens. In the stag, axis, and buffalo they are smooth, and of a regularly oval shape, and have a central cavity commu nicating by large openings with smaller cavi ties ; each has a single duct, which terminates generally behind the corresponding vas de ferens. The only difference in this class is in regard to size ; for in the chamois each is as large as a pullet's egg, and contains a propor tionably large cavity ; so that it has been occasionally mistaken for a reservoir of semi nal fluid. In the seal, amongst the quadri remes, it resembles that of the otter. In the cetacea there is a large glandular mass, covering a large portion of the first part of the urethra, especially at the upper part, covered by a strong muscle. When a section is made, it is found to consist of large cells ; its ducts open separately by numerous orifices on the urethra.
In the marsupial sub-class, as in the kanga roo, the prostate is found surrounding the com mencement of the urethra, of large size, and conical in shape, with base behind, apex in front ; it is surrounded by a strong musculo membranous capsule. It exceeds in diameter the contracted bladder, and is made up of tubes ramifying perpendicularly to the urethra, which subdividing terminate in minute cceca upon the surface of the gland. It presents a
similar arrangement in the opossum ; whilst in the wombat its existence is doubtful.
Carus has described in birds a dilatation of the vas deferens, a rudimentary vesicula semi nalis, and a small gland like a prostate near the termination of the vas deferens. This is not admitted by Owen. In the ornithorynchus paradoxus we find two round glandular bodies representing Cowper's glands, but which may be fairly regarded as a rudimentary prostate.
Amongst amphibious reptiles," glands ana logous to the prostate, or Cowper's glands, are found. In the salamander they are com posed of two lobes ; one placed horizontally, arid the other vertically ; the former, in the common salamander is heart-shaped, with the point behind ; and in its centre a fissure is seem The vertical lobe is raised obliquely towards the dorsal aspect, so that an interval is left between them for the passage of the kidneys ; a muscle separates the two.
In the black salamander, each gland is com posed of two lobes. In the Tritons the part of the prostate which corresponds with the inferior lobe is still more complicated; it forms the wall of the vestibulum in the shape of a cup. Besides this, there are two pelvic pros tates corresponding to the vertical lobe of the vestibular prostate of the salamander ; they occupy the dorsal aspect of the vestibule and the pelvis, and each is subdivided into two lobes. Their excretory ducts open in the mesian line of the furthest point of the vesti bule. The Tritons have a third prostate occu pying a large portion of the abdominal muscles under the peritonmum. In structure they re semble those of the hedgehog.— (Cuvier.)