Corpus Spongiosum and the Corpus Cavernosum. 19 



Fig. 3. 



Thin Transverse Section of the Corpus Spongiosum (Man), prepared in 

 Alcohol. Treated first with Carmine, and afterward with Acetic 

 Acid, and preserved in Glycerine. Magnified 160 Diameters. 



In the centre of the picture at a, is seen a transverse section of the arterial 

 profunda? corporis spongiosi. At b, the inner coat of the artery. At c, c, its very 

 darkly-stained middle coat, with the nuclei of its individual muscular fibres. At 

 d, d, its transparent external connective-tissue coat. The artery is surrounded by 

 quite a number of organic muscular bundles, like a tube surrounded by a bundle 

 of staves, e, e, e, e, e. At many points may be seen a portion of these fasciculi con- 

 necting and mixing with the muscular coat of the artery, as, for example, at e*. 

 The muscular bundles surrounding the arteries are so distinct from the other longi- 

 tudinal muscular bundles that they must be recognized as a set belonging exclu- 

 sively to the arteries. The meshes of the spongy substance, g, g, g, g, are seen to be 

 lined by pavement epithelium, h. 



cavernosum than in the corpus spongiosum. In the latter body 

 they are most numerous in the bulbous and posterior portions. 



In most of these terminal knobs can be seen a triple fissure, the 

 form of a Y — like the three-horned figure in the crystalline lens of 

 the human eye (Fig. 7). The smaller branches often present but 

 a simple transverse fissure. Stilling is inclined to regard these fis- 

 sures as the openings or mouths of the arteries, which are closed in 

 the ordinary condition, but in the state of erection are opened and 

 empty the arterial blood into the venous cavities or cells. 



