Corpus Spongiosum and the Corpus Cavernosum. 17 



and that at those points where one fasciculus turns from one hori- 

 zontal plane into another, others arise and continue in an analogous 

 manner the horizontal course left by the first, and thus contributing 

 to the formation of a more or less interrupted muscular ring upon 

 the periphery of the corpus spongiosum.* 



In the section of the corpus spongiosum before you can be seen 

 the arterise profundae corporis spongiosi, equidistant from the ex- 

 ternal fibrous covering and urethral canal in each lateral half of the 

 corpus spongiosum. In this instance they are almost on a level 

 with the urethra, though sometimes we find one artery a little 

 below, the other a little above, the level of the urethra. At the 

 bulbous portion we always find the arteries below the level of the 

 urethra, because of the greater thickness of the parts below the canal 

 at this part. 



Fig. 1 (pp. 22 and 23). 



Thin Transverse Section of the Corpus Spongiosum Urethra. Taken from 

 the Penis op a man aged twenty-seven, midway between the Glans and 

 Bulbous Portion. Prepared in Alcohol, and treated with Carmine. 

 Magnified 20 Diameters. 



The albuginea, or external connective-tissue sheath of the corpus spongiosum, 

 is shown at A A' A" A'". The upper half, which is connected with the corpus 

 cavernosum, is seen at A A' A" ; the lower half at A, A'", A". It is abundantly 

 interspersed with (dark) fasciculi of organic muscles, a, a, a, a, which do not run 

 completely around the periphery of the corpus spongiosum, but form only frag- 

 ments of a muscular ring. These fasciculi are continuous with those seen in the 

 substance of the corpus spongiosum at B, B, B, B. At A*, Af (between A and A'), 

 may be seen such fasciculi, extending from the albuginea directly into the sub- 

 stance of the corpus spongiosum. At b, b, b, can be seen the cut surfaces of a large 

 number of muscular bundles appearing as round, oval, or irregularly-shaped dark 

 spots. At c, c, c, c, may be seen other muscular fibres running in continuity. The 

 latter run in a parallel direction with the section, while the former run in a ver- 

 tical direction, and are consequently cut by the section. Between these bundles 

 of muscles can be seen, d, d, d, d, innumerable empty spaces or meshes of irregular 

 shape. The walls of these spaces have become separated in preparing the speci- 

 men, while during life they are generally in immediate contact. These spaces are 

 lined with pavement (Pflaster) epithelium, which can be distinctly seen, in suit- 

 able preparations, with a magnifying power of 60 to 200 diameters. Some of these 

 meshes are quite near the mucous membrane, separated from it only by a thin 

 layer of connective tissue, i. e. in the upper wall of the urethra in this figure. 

 Transverse section of the corpus spongiosum will show as a rule two large arteries, 

 e e, the arterise profunda corporis spongiosi. Each of these is surrounded by a 

 number of organic longitudinal muscular bundles, e*, e*, which appear as round 

 masses, in whose centre the artery passes. In the middle of the section is seen an 

 empty space, C, the canal of the urethra. The epithelial covering of the mucous 

 membrane is indicated at /, /, /, and is seen extending into its lacunas. The exist- 

 ence of a real space in the accompanying figure is the result of the preparation. 

 It does not exist during life. At g, g', g", r/t, g*, is seen the cut surface of a lacuna 

 which extends deeply into the substance of the corpus spongiosum at g*, and sends 

 off several branches from its sides g', g", gf. The largest meshes are at the ex- 

 ternal portions of the corpus spongiosum ; the smaller ones near the urethra. The 

 substance of the corpus spongiosum near the urethra is more transparent than the 

 rest, because it consists of finer fibres than the parts more external. 



* B. Stilling, ' Harnrohren-stricturen,' Fig. 1. 



c 2 



