THE KECTUM. 417 



projects inwards from it in the middle line, opposite the tube of the imperfect 

 urethra ; this is best marked for a short distance in front of the se P tum ; 

 bulli, and assists in dividing that part into two lobes. The trabe- 

 cular bands are much finer, and more uniform in size than in the trabecuise. 

 corpora cavernosa. 



Blood-vessels. The arrangement of the blood-vessels in the Blood- 

 erectile structure of the corpus spongiosum is similar in the bulb vessels : 

 to that in the corpora cavernosa ; but in the rest of the spongy- 

 substance the arteries are said to end in capillaries in the usual way. 



The arteries are derived from the pudic on each side ; a large source of 

 one behind, the artery of the bulb (p. 251), enters the upper surface artenes 5 

 of the bull) ; and several in front, offsets of the dorsal artery of the 

 penis, penetrate the glans. Kobelt describes another branch to the 

 fore part of the bulb. 



Most of the vei?is, including those of the glans, end in the large termination 

 dorsal veins of the penis, some communicating with veins of the of the vems> 

 cavernous body ; others issue from the bulb, and terminate in the 

 pudic vein. 



Nerves and lymphatics. The nerves of tbe penis are large, and Nerves, 

 are supplied, as previously described, by both the spinal and 

 sympathetic nerves. The superficial lymphatics of the integuments, Lymphatics, 

 and those beneath the mucous membrane of the urethra, join the 

 inguinal glands ; the deep accompany the veins beneath the 

 subpudic arch, to end in the lymphatic glands in the pelvis. 



THE RECTUM. 



Dissection. The rectum is to be washed out and then distended To prepare 

 with tow, and the peritoneum and the loose fat are to be removed the gut ' 

 from it. 



This portion of the intestine is about five inches in length. Its Rectum : 

 lower half is commonly dilated, especially in old people, and the length; 

 anal canal in which it terminates is the narrowest part of the large dimensions ; 

 bowel. It is sacculated, although not so distinctly as the colon ; the saccuii. 

 pouches are arranged in two rows, right and left, and they become 

 larger and less numerous towards the lower end. 



Structure. The rectum contains in its wall a peritoneal, a same coats 

 muscular, a submucous, and a mucous stratum ; and the muscular as * n *ke 

 and mucous coats have certain characters which distinguish this intestine: 

 part of the intestinal tube. 



The peritoneum forms but an incomplete covering, and its Peritoneum, 

 arrangement is referred to in the description of the relations of the 

 pelvic viscera (p. 386). 



The muscular coat consists of two layers of pale or unstriated Muscular 

 fibres, viz., a superficial or longitudinal, and a deep or circular. c 

 The longitudinal fibres are mainly collected into anterior and hasiongi- 

 posterior bands, which spread out and increase in thickness below : tudmal 

 the anterior band is the broader, and is formed by the union of two 

 of the bands of the colon, while the posterior is the continuation of 

 the band lying along the attached border of the colon. These 



D.A. E E 



