ANATOMY. 



There is a small body, partly distinct 

 from the testis, and placed behind it, 

 called the epididymis. 



The substance of the testis is found by 

 dissection to be soft; and it is composed 

 of a congeries of very minute tubes, 

 named tubuli seminiferi, which may be 

 unravelled and separated by macerating 

 in water, although they were previously 

 connected into the appearance of a fleshy 

 mass. The diameter of these tubes is 

 estimated at l-200th of an inch ; and the 

 number of them at about 60,000. If they 

 were joined together, they would form a 

 tube of about 5000 feet long. These 

 tubes terminate ultimately in a single 

 small canal, which, by its innumerable 

 turns and windings, makes up the whole 

 epididymis. If this could be completely 

 drawn out, it would be about 30 feet 

 long. It increases rather in size towards 

 the end of the epididymis, and leaves 

 that body in the form of a simple and 

 unconvoluted tube, assuming the name 

 of vas deferens, and ascending along the 

 back of the spermatic chord to the abdo- 

 men. It can be readily distinguished in 

 that situation in the living person : it feels 

 like a hard chord, about the size of a 

 crow quill. 



When the spermatic chord has entered 

 the abdomen, the vas deferens leaves it, 

 runs along the back of the bladder, and 

 opens into the commencement of the 

 urethra. 



Vesiculce seminales. Before the vas de- 

 ferens terminates in the urethra, it is 

 joined at an acute angle by the canal of 

 the vesicula seminalis. 



These vesicles are two soft bodies, ly- 

 ing in contact with the under surface of 

 the bladder, and formed, each of them, 

 by the convolutions of a single membran- 

 ous tube. An injected liquor thrown into 

 the vas deferens will pass into the vesi- 

 cula seminalis, rather than into the ure- 

 thra ; for the opening into that canal is 

 extremely small, while the communica- 

 tion with the vesicula is large and free. 

 Hence it has been supposed that these 

 vesicles are reservoirs for retaining the 

 fluid formed in the testicles until it is 

 wanted. 



Mr. John Hunter has however pretty 

 clearly demonstrated that the vesiculx 

 are not intended to contain semen, but 

 that they secrete a peculiar fluid, to sub- 

 serve the purpose of generation. See his 

 "Observations on certain parts of the 

 Animal Economy." 



Prostate gland. The origin of the ure- 

 thra is surrounded bv the substance of 



this gland, which in sue and form muck 

 resembles the chesmit. Numerous open- 

 ings are found in the commencement ef 

 the urethra, which discharge on pressure 

 a whitish viscid fluid, secreteu in the 

 substance of the prostate. A portion of 

 the gland projects into the lower part of 

 the commencement of the urethra, and 

 has received the name of caput gallinagi- 

 nis: it is on this that the openings of the 

 canals, formed by the junction of the vasa 

 deferentia and vesiculae seminales, are 

 found. 



The urethra is subservient to two pur- 

 poses; the expulsion of the semen in the 

 act of copulation, and the conveyance of 

 the urine from the bladder. Its surface is 

 perfectly smooth, and is covered and pro- 

 tected by a mucous secretion. The dia- 

 meter of this canal varies slightly at dif- 

 ferent parts, but may be stated generally 

 at about one-eighth or an inch. At its 

 first departure from the bladder, it is 

 surrounded for one inch by the prostate ; 

 it is then continued as a simple membran- 

 ous tube, but surrounded by muscular 

 fibres for another inch ; this is called the 

 membranous portion of the urethra. In 

 the rest of its passage it is surrounded bv 

 a vascular substance, called corpus spon- 

 giosum ; this is accumulated in a consi- 

 derable mass at its commencement,where 

 indeed the urethra is broader than in any 

 other situation, and this is called the 

 bulb. The seminal and prostatic liquors 

 are poured into the bulb of the urethra, 

 and are forcibly expelled from thence 

 by a sort of convulsive contraction of a 

 muscle, whose fibres surround this part 

 of the canal; the ejaculator seminis. 

 The glans penis is nothing more than a 

 portion of the same vascular mass, which 

 surrounds the rest of the urethra, cover- 

 ed by a very delicate, sensible, and finely 

 organized integument. 



The bulb, corpus spongiosum, and 

 glans, are susceptible of the same erec- 

 tion as the body of the penis; which is 

 indeed essential to the performance of 

 their functions, m conveying the fecun- 

 dating liquor into the body of the female, 



The penis consists of two bodies, call- 

 ed crura, or corpora cavenosa, which 

 arise separately from the bones of the 

 pelvis; but join so as to form afterwards 

 a single organ. Each crus consists of a 

 very strong and dense ligamentous tube,, 

 filled internally with cellular substance, 

 into the cells of which tiie arteries open, 

 and from which the vt.ins coian.cnce 

 The arteries pour the i.iuod into these 

 organs with great energy, in obedience' 



