ORGANS OF THE BODY. 567 



In the middle or membranous portion of the passage under the mucous 

 membrane a long-meshed cavernous tissue again presents itself. The 

 organic muscular layer, on the other hand, is weaker, and covered by 

 bundles of the musculus urethralis, which consists principally of trans- 

 versely arranged bundles of striped fibres. 



But the unstriped muscular tissue of the pars cavernosa is even less 

 developed still. Here the mucous membrane is covered with cylinder 

 cells, which give place to a covering of flattened epithelium at a greater 

 or less distance from the mouth of the urethra. 



The last-named portion of the urethra contains farther little depres- 

 sions or pits, the lacunce Morganii, which are not glandular in their 

 nature ; also isolated small and ill-developed racemose glandules, known 

 as glands of Littre, whose vesicles and ducts are lined with cylinder 

 epithelium. These do not appear to exist in the pars niembranacea (Henle). 



Just a few words in regard to the skin of the penis. This is thin and 

 loose down to the free edge of the prepuce, and is possessed of fine downy 

 hairs, which decrease in length below, and into whose follicles sebaceous 

 glands empty themselves. Its very elastic subcutaneous areolar tissue 

 presents longitudinal bundles of involuntary muscle-fibres, prolongations of 

 the tunica dartos of the scrotum, and is quite devoid of fat-cells. This 

 subcutaneous tissue invests the whole organ 'down to the base of the 

 glans : it is known as the fascia penis. At the root of the member it is 

 condensed into an elastic band the ligamentum suspensorium penis. 



The connective-tissue binding the two laminae of the foreskin together 

 manifests the same distensibility, but is destikite of fat : it is intermixed 

 with muscular elements. 



The surface of the glans is covered by a delicate membrane, closely 

 adherent to the cavernous tissue beneath. This membrane is possessed 

 of very numerous papillae arranged in rows converging towards the orifice 

 of the urethra, and obscured by the flattened epithelium covering of the 

 part. On the corona glandis we may frequently observe larger papillae, 

 measuring from, 0*9 to 0*5 mm., and appearing as white specks through 

 the membrane or bulging out the latter. 



The internal leaf of the foreskin, smooth and without wrinkles, presents 

 all the characters of a mucous membrane. It is quite destitute of hair 

 and convoluted glands, but is supplied with numerous tufted papillae. 



On the inner surface of the prepuce are situated a number of sebaceous 

 follicles, known as Tysoris or Littre's glands. These occur in varying 

 number and form, and are found at times also upon the surface of the glans, 

 especially in the vicinity of the fraenum. Their secretion mixes with the 

 epidermal scales of the part when shed, and so assists, though, in a very 

 minor degree, in producing that tallowy substance, known as the smegma 

 preputii, which collects sometimes underneath the foreskin. 



Each of the corpora cavernosa is enveloped in a nbro-elastic tunic, con- 

 taining but few muscular elements, the tunica albuginea, v. fibrosa, from 

 which innumerable bands and septa are given ofi" internally, consisting of 

 ordinary and elastic connective-tissue fibres, with a number of muscular 

 elements. These bands, then, undergo repeated subdivision, and unite 

 in every conceivable way; so producing a system of cavities communicat- 

 ing with one another, like those of a sponge, and lined throughout with 

 vascular cells or endothelium. Thus a peculiar venous receptical is 

 formed for the blood. 



The several cavernous bodies in man resemble each other, as a rule, in 

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