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 271 Part VI. A N A T O M Y and it refembles in fome meafure an arch fupported by edge of this feptum, and thereby braces down the middle its center or frame. It is more contracted at the middle, of the cutaneous portion, which from thence appears to than at the extremities, by which it is clofely united to have in part two cavities. The aponeurotic or ligamentary expanfion of the darthofe of the te/licle. Between its extremities it does not immediately touch tos is fixed in the ramus of the os pubis, between the the tefticle, but is only loofely connedted to it, by the mufculus triceps and the origin of the corpus cavernoduplicature of a very fine and almoft tranfparent mem- fum of the fame fide, all the way to the lower part of brane, as by a kind of ligament. This membrone is the the fymphyfis of thele bones. continuation and duplicature of the tunica albuginea or The vafa deferentia are two white folid flatted tubes, proper coat of the tefticle, which having fupplied the one lying on the right fide, the other on the left. From place of a ligament to the epididymis afterwards in veils it. the epididymis, of which they are continuations, each of The epididymis is flat, a little concaye on the under them runs up in the cellular vagina of the fpermatic veffide, or that next the teliicle, irregularly convex on the fels, as high as the openings in the abdominal mufcles j upper fide, or that turned from the tefticle; and thefe the blood-velftls lying forward, and the vas deferens betwo fides are diftinguiftied by two angular edges ; by the hind them. innermoft of which, it is connedled to the tefticle, in the This fafciculus, thus formed by the blood-veffds, vas manner already faid; but the outer edge and flat fide deferens, and their common covering, is termed the fpermatic rope. The covering is fmoother on the outer are loofe and free. The anterior extremity or head of the epididymis arifes than on the inner fide, and for that re Ton it has been from the tefticle; and the pofterior extremity or tail, looked upon as a vagina ; the internal fubftance of which which likev/ife adheres very clofely to it, is incurv^ted is moft cellular, and conneds all the veflels together,from behind, forward, and a little upward, and contrac- while the external forms a covering to invert them. ting by degrees, forms a particular canal, termed vas The vas deferens having reached the membranous ladeferens, which lhall be defcribed after the fcrotum. mina of the peritonaeum, where that lamina runs over The fcrotum is the cutaneous covering of the teftes. the orifice of the vagina, feparates from the blood vefOutwardly, it is a bag common to both, formed by a fels, and runs backward,- in form of an arch, in the cel-7 continuation of the fkin of the neighbouring parts, and lular fubftance of the peritonaeum, as far as the neareft commonly very uneven, having a great number of rugae fide of the bladder. on its outer furface. Interiorly it is fldhy, and forms a It pafles afterwards behind the body of the bladder, mufcular capfula for each tefticle, termed dartos. to which it adheres very clofely, as alfo to the lamina of The exterior or cutaneous portion of the fcrotum is the peritonaeum which covers it, and then continuesnearly of the fame ftrufture with the fkin in general, of its arched courfe towards the neck of the bladder, where which it is a continuation; only it is fomething finer, both vafa deferentia meet, and their arches terminate. and it is likewife plentifully ftored with febaceous glands In this courfe, the vas deferens pafles behind and crofand bulbs or roots of hairs. fes the neighbouring umbilical artery; crofles the extre-. Though it is a common covering for both tefticles, it mity of the ureter of the fame fide, in its pafl'age beis neverthelefs diftinguiflied into two lateral parts by a tween that extremity and' the bladder; and having got fuperficial and Uneven prominent line which appears like behind the bladder, it meets the vas deferens of the oa kind of future, and from thence has been termed raphe. ther fide between the infertion^ of the ureters, and they This line is a continuation of that which divides in run down together to the neck of the bladder. the fame manner the cutaneous covering of the penis ; This canal, which at the origin of the epididymis is and it is continued through the perinasum, which it di- pretty large and plaited, becomes immediately afterward vides likewife, all the way to the anus It is only fu- fmaller and fmoother, and continues in that form till it perficial, and does not appear on the infide of the Ikin. gets behind the bladder,, where it begins again to be larThe inner furface of this cutaneous bag is lined by a ger and more uneven. very thin cellular membrane, through which bulbs and It arifes from the angular portion or pofterior extremiglands appear very diftin&ly when we view its infide. ty of the epididymis, and from thence runs forward in a. The dartos, or flefliy portion of the fcrotum, is a true very oblique courfe, on the pofterior half of the epididycutaneous mufcle ; the fibres of which are for the moft mis, where it is a little ineurvated as it joins the backpart ftrongly connetfted to the fhin, running through the fide of the fpermatic veflels. cellular fubftance which lies between thefe two portions The cavity of the vas deferens is cylindrical, though* in place of a membrana adipofa, but without the leaft: the whole tube is flat, and its external circumference oappearance of fat. This ruufcle is thin, and by the dif- val, and the cavity inlarges as it paftes behind the bladpofition of its fibres forms a bag. with two cavities, or der. The termination of thefe canals muft be referred two fmall bags joined: laterally to each other, and con- to the hiftory of the urethra. tained within the cutaneous portion. The particular coverings- of the teftes are commonly ' The lateral parts of thefe two bags, which are turned called coats; and they are reckoned to be three in numfrom each other, are longer than thofe which are joined ber; the tunica mufculofa, named cremafter, vaginalis together; and by this union a feptum is formed between and albuginea. The firft two are common to each tethe teftes, which may be called mediaftinum fcroti. fticle, and to the fpermatic rope that belong? to it ; and. The raphe or future already mentioned adheres to the the third is peculiar to the tefticle. alone. The