974 MALE ORGANS OF GENERATION. 



nales at the sides with the vasa deferentia interposed, and behind by the 

 Hue of reflexion of the peritoneum from the bladder to the rectum, rests 

 mmediately on that intestine. The seminal vesicles themselves are also 

 supported by the sides of the rectum, but they are separated from the 

 bowel by a layer of the recto- vesical fascia, which holds them to the base of 

 the bladder. 



The sacculated appearance of the vesiculee seminales is owing to their 

 peculiar formation. Each consists of a tube somewhat coiled and repeat- 

 edly doubled on itself, and firmly held in that condition by a dense fibrous 

 tissue. When unrolled, this tube is found to be from four to six inches long, 

 and about the width of a quill. Its posterior extremity is closed, so that it 

 forms a long cul-de-sac ; but there are generally, if not always, several 

 longer or shorter branches or diverticula developed from it, which also end 

 by closed extremities. Its anterior extremity, which forms the fore part of 

 the vesicula, becomes straight and narrowed, and ends opposite the base 

 of the prostate by uniting on its inner side, at a very acute angle, with the 

 narrow termination of the corresponding vas defereus to form a single canal, 

 which is the common seminal or ejaculatory duct. 



In structure, the vesiculse seminales resemble very closely the adjoining 

 sacculated portions of the vasa deferentia. Besides an external fibro-areolar 

 investment, connected with the recto-vesical fascia, they have a proper coat, 

 which is firm, dense, and somewhat elastic, and consists of rigid white 

 fibres and of others of a deep yellowish-brown hue. Muscular tissue is 

 found in their walls, at least on the posterior aspect, where longitudinal 

 and transverse bands pass over them from the muscular wall of the bladder 

 (Ellis and Kolliker). The mucous membrane is pale, or has a dirty 

 brownish-white colour. It is traversed by multitudes of fine rugae, which 

 form an areolar structure resembling that seen in the gall-bladder, but deeper 

 and composed of much finer meshes. The epithelium of the vesiculse is of the 

 squamous kind ; its particles have a granular character. 



The seminal vesicles serve as receptacles or reservoirs for the semen, as is 

 easily proved by a microscopic examination of their contents ; but, besides 

 this, it is supposed by some that they secrete a peculiar fluid which is incor- 

 porated with the semen. 



The common seminal or ejaculatory ducts, two in number, are formed on 

 each side by the junction of the narrowed extremities of the corresponding 

 vas defereus and vesicula seminalis, close to the base of the prostate gland. 

 From this point they run forwards and upwards, at the same time approach- 

 ing each other, and then pass side by side through the prostate between its 

 middle and two lateral lobes. After a course of nearly an inch, during 

 which they become gradually narrower, they end in the floor of the prostatic 

 portion of the urethra by two small slit-like orifices placed one on each 

 prominent margin of the verumontanum close to the opening of the sinus 

 pocularis. For a short distance the ejaculatory ducts run in the substance 

 of the walls of this sinus. 



The coats of the common seminal duct, as compared with those of the 

 vas deferens and vesicula, are very thin. The strong outer tunic almost 

 entirely disappears after the entrance of the ducts between the lobes of the 

 prostate, but muscular fibres may be traced into the prostatic portion ; and 

 the mucous membrane becomes gradually smoother, and at length passes 

 into that of the urethra. The muscular fibres of the duct, according to 

 Heule, are separated in the prostate to form the trabeculee of a layer of 

 cavernous tissue. 



