SECT. I99.] VESICULJE SEMINALES : PROSTATE. 439 



still more attenuated, but present, even at the extreme termination, 

 muscular fibres, intermingled with a considerable quantity of con- 

 nective tissue and elastic fibrillae. The seminal vesicles have their 

 walls considerably thinner than those of the spermatic ducts, but 

 possess a similar structure; the mucous membrane, which is very 

 vaseular, is covered all over with reticulated depi"essions. The 



rainal vesicles arc surrounded externally by an envelope, which 

 is composed, in part, of connective tissue, and, in part, especially 

 upon the posterior surface, of distinct muscular fibres. This en- 

 velope also extends inwards, between the separate convolutions of 

 these canals, and unites them, while at the lower ends of the 

 s initial vesicles, it passes from one to the other as a broad mus- 

 cular band ; this has been recently observed also by V. Ellis, who 

 calls this band the compressor vesiculce et ductus seminis. The 

 contents of the seminal vesicles consist, normally, of a clear fluid, 

 somewhat viscid in consistence, which coagulates immediately after 

 death into a soft jelly, but subsequently becomes again quite fluid. 

 This contains a protein compound, easily soluble in acetic acid, 

 which is obviously identical with that contained in the fluid of the 

 ejaculated semen. In common with many other observers, I have 

 frequently found spermatozoa in the seminal vesicles, although the 

 main function of these appendages is doubtless secretory. The 

 nerves of the seminal vesicles are derived from the sympathetic 

 and spinal cord, and spring directly from the dense plexus seminalis, 

 whose fibres partly enter into the coats of the seminal vesicles, 

 partly pass to the prostate gland, and are not further traceable. 

 The prostatic plexus, thus formed, is reinforced by filaments from 

 the vesical and lower pelvic plexuses. 



The prostate, according to my own observations, which are con- 

 firmed by V. Ellis, and partly also by Jarjavay, is a very muscular 

 organ, the glandular substance scarcely constituting more than 

 one-third, or the half of the entire mass. Proceeding from within 

 outwards, Ave first meet with the thin mucous membrane, whose 

 epithelium is composed of two layers of cylindrical cells, and in 

 intimate connection with this membrane we next observe a yel- 

 lowish layer of longitudinal fibres, which partly extends from the 

 trigonum vesica to the caput gallinaginis, but is, in another part, 

 unconnected with the muscles of the bladder; this layer consists 

 of connective tissue, elastic fibrillae, and smooth muscular fibres in 

 equal proportions. It is followed by a thick stratum of circular 

 fibres of the same structure, which is connected with the sphincter 

 vesicae, and extends as far as the caput gallinaginis, and which I 



