GENERATION. 



.nuia penis rmd btlaw tlic canal of tlio urctlira, fomctiincs 

 hoariiig a (light appcaranco of diviiiou into two laloral pails 

 liy a middle linr, and terminating behind by a rounded end. 

 I'he bulb coriefponds only to the inferior furface of tlie 

 uivlhra ; but a thinner layer of the corpui fpongiofuin, con- 

 tinued from the bulb, com tg the urethra on all iides in Iront 

 of that body to the end of the canal. Here it is. a^fain in- 

 ereafed in quantity, and reflected over the anterior extremity 

 of the corpus cavcrnofuni penis, to form the glan".. The 

 fpoiigv fubilance furrouiids the urellira uniformly on all iides. 

 It ii clofely connected to the corpus cavernofum above by 

 cellular fubftance, and by vefltls which are fccn when the 

 uretiira is detached from its channel ; below and on the fidt s 

 it is covered by a cellular (heath, common to it with Die 

 corpus cavernofum penis. Tlic external lurface of liie 

 corpus fpongiofum confifts of a thin but compact: fibrous 

 layer; and the interval between this and the mucous mem- 

 brane fecnis to be filled by a very lino cellular net-work, the 

 cells of which contain r'cnous blood. The tenuity of tin- 

 external layer occalioiis tiie part to polfefs a livid colour, us 

 the tint of the blood is difcernib!?. Thi. net-work is 

 covered in the glans by a higlvly organized fpecies ot .(km, 

 through whicli the colour of the venous blood is not d'.f- 

 cernible. The corpus fpongiofum does not coniill, ac- 

 cording to the common opinion, of a cellular texture ; but 

 it is made up of very fmall and repeatedly convoluted veins, 

 as may be afcertained dilHnftly enough by infpefting atten- 

 tively the furface of it, when fucccfsfuUy injected : this 

 ■Tiruftare is inore evident in foir.e animals, as particularly in 

 the dog. The bulk of the corpus fpongiofum depend* on 

 the quantity of blood which it contains ; and this part admits 

 of the fame diilinclion, as the fpongy fubilance of the cor- 

 pora cavernofa penis, and for the fame purpofes. Air, im- 

 pelled into any part, fmds its way readily over the wkole ex- 

 tent of the fubftance, and the fame circumilance may be ob- 

 ferved of injection. It may be readily injefted from the 

 large vein at the back of the penis ; but the valves fometimcs 

 prevent the fuccefs of this attempt. 



The canal of the urethra is lined by a mucous membrane, 

 continuous with the lining a£ the bladder at one extremity, 

 and with the cutaneous covering of the glans at the other, 

 and fending prolongations into the mucous finufes of IVIor- 

 gagni, the dacls of Cowper'e glands, the ejaculatory dufts, 

 and thofe of the proltate. Its furface is perfectly fmooth, 

 excepting the longitudinal wrinkles, which are effaced by 

 extcniion. The colour is a bright red at the external orifice, 

 n-i.d in the foUa navicularis : in other parts it appears pale, 

 v hen the blood lias been expreffed from the corpus fpongio- 

 fum. But the injection of coloured fluids proves that it re- 

 ceives every where an abundant fupply of blood-veffels. Its 

 fiibltar.ce is very thin, and the opinion of its being covered 

 1)V a continuation of the epidermis does not feem to be at all 

 well-founded, as there is a well marked line of feparation at 

 the g'ans, and no cuticle can be thewn in the canal. The 

 external furface is rough and cellular for its connection to 

 furrounding parts. No appearance of mufcular ftrufture 

 can be difcerncd in any part of the membrane. The intro. 

 duction of an inftrument iliews this membrane to pofTefs 

 acute feniibilitv", and the repetition of tiie practice evinces 

 the force of habit in blunting fuch feelings. The firft time 

 of palhng a bougie or found is fometimes attended v.ith 

 fainting, ar.d almoit alwavs with (harp p-.'.in, but after a [c\v 

 times, no unpleafant fenfation is excited. Thepaffage of the 

 urine is attended ordinarily with no fenfation ; but this be- 

 comes moll at utely painful when the membrane is inflamed. It 

 , has been much difputcd whether or no this canal pofTefs a 

 f ontraftile power in its own lining. The phenomena are 



ftrongly in farour of the afEi-mative, although no mufcular 

 fibres have been demonftrated. The temporary obltruttion 

 to the flow of urine, under circumftanCLS of difeafc, and 

 the fudden celfation of this inconvenience, can hardly be 

 expl.<ined without allowing a contractile force to the mem- 

 brane. The expulfion of inilruments from the canal is 

 anotlier plicnoinenonof the lame kind. That the urethra is 

 extenlible,andthat it returns again to itsoriginal fi/e, isproved 

 b^' tl'.e pailage of inftruments. Haller dates that chemical 

 il;mulaiits v.-llcai:fc it to contraft. 



'i'heg/fifis is the body furinouiiting the anterior and upper 

 part of the corpus cavernoium penis, and forming the front 

 extremity of the organ, of which it augments tlie length 

 in a trivial degree. It has t!ie form of a cone, (lightly 

 flattened from before backwards, with its bafe very oblicjue- 

 Iv truncated. Its apex prrfents the aperture of the urethra 

 already defcribed. Below this, is placed the frenum coimeCl- 

 ing it to the prepuce ; and on each !ide of this fold it fwcUs 

 into a fmall convex protuberance (ccUiculi glandis). This 

 partis called by Haller " fenins acerrimi fedes.'' The 

 glans cannot be laid to extend below the urethra, as that 

 part belongs to the corpus ipongiofum. Since the bafis is 

 fo obliijueiy truncated, the depth ot the organ is very incon- 

 fiderable nt the two convexities already named ; but it is 

 much mure confiderable above, where it is produced overtke 

 corpus cavernofum, and terminated by a thxk rifing edge 

 of a femi-lunar outli.ne, with the convexity turned back- 

 wards, called tlie corona glandis. This margin, fulEcicntly 

 thick and prominent to elevate tiie integuments, and caule a 

 perceptible rifing externally, forms the front boundary of a 

 cul-de-iac, or gutter, caufed by the reflection of the inner 

 membrane of the prepuce over the glans. Below, the corona 

 glandis is interrupted by a fmall groove, which extends to 

 the orifice of the urethra, and gives aLtnchment to the fold 

 which forms the frenum. In iome lubjeiSts tl:is groove is 

 hardly perceptible. The colliculi glandis are continuous 

 below with the corpus ipongiofum ; the bails of the glans is 

 hollowed out, and the anterior extremity of the corpus ca- 

 ve.'nofum penis is received iiixo the concavity. In confe- 

 quence of this ftruClure, although the glans appears to be 

 an inch or more in length, it makes very little addition to the 

 length of the penis. 



The fubftance of the organ confifts of a fpongy matter 

 fimilar to and continuous from that of the urethra. Air 

 or iniedted fluids pafs readily from one into the other. This 

 matter is made up, as in the urethr.', of convoluted veins, 

 and it admits of the fame changes of laxity and ereftion 

 from the fame caufes. Sometimes there is an appearance as 

 if the corpus fpongiofum urethrje and the glans were fepj. 

 rated from each otlier by a feptum. The fubilance of the 

 glans is always more dcnfe, and contains lefs blood than that 

 of the urethra. The furface of the organ is covered by a 

 very valcular and dehcate production of the integuments, 

 continuous towards the apex of the glans with the raucous 

 lining of the urethra, and at its balls with the inner layer of 

 the prepuce. This covering is very thin, and imooth and 

 (oft to the touch. Its external furface is compofed of a de- 

 licate epidermis; this is fucceeded by a layer of the true 

 ik'm, of a very ibft and delicate ilrudture, covered with nu- 

 PAerous fniall villous procefTes, which are mofl diilinCtly feen 

 about the coivr.a glandis. The moil favourable method of 

 obterving thele villi is to plunge tlje part in boiling water, 

 which feparates the cuticular coi-ering; they are then vili- 

 ble in valt numbers over the whole furface, giving it an iirc. 

 gularity in its appearance. This circumftance in the ilruc- 

 tureof the glans was firll demonftrated by Albinus (Annol. 

 Acadcm. lib. iii.), and is admitted by Ruyfch and Winilow, 



jilthough 



