MALE GENITAL ORGANS OF THE DOG 



507 



forms a rounded enlargement, the bulbus glandis; anteriorly it is cylindrical, 

 smaller, and pointed at the extremity. Just in front of the bulbus glandis there is 

 a thick circular layer of glands, forming the annulus glandularis (Schmaltz). 

 The two dorsal veins arise from the bulbus glandis, pass backward on the dorsum 

 penis, and unite at the ischial arch. A small muscle (M. compressor venae dorsalis 

 penis) arises from the tuber ischii on either side; the two converge on the dorsum 

 penis near the bulbus glandis. They compress the dorsal veins, and may also tend 

 to elevate the penis and thus assist in copulation. The other muscles offer no 

 features worthy of special description. 



The prepuce forms a complete sheath around the anterior part of the penis. 

 The outer layer is ordinary integument. The inner layer has the character of a 



Fig. 405. — Extkrnai. Genital Organs of Male Dog, Ventro- 



LATKRAL ViEW OF PrEPARATIO.N. 



1, Scrotum; /', tunica vaginalis; 2, epididymis; 3, vascular 

 part of spermatic cord; 4, vas deferens; 5, prepuce; 6, glans penis; 

 6', corpus cavernosum penis; 7, bulbus glandis; 7', contour of bul- 

 bus in erection; S, ischio-cavernosus muscle; a, acetabulum; 6, ob- 

 turator foramen. (After Elleiiberger, in Leisering's Atlas.) 



Fig. 406. — Internal Genital Organs op 

 M.\LE Dog. 

 /, Urinary bladder; S, ureter; 3, vas 

 deferens; 4, prostate; 5, urethral muscle; 6, 

 bulb of urethra; a, abdominal wall; b, ilium; 

 c, ischium. (After EUenberger, in Leisering's 

 Atlas.) 



glandular mucous membrane; it is thin and reddish in color. The penile layer is 

 glandless. In the fundus of the prseputial cavity there are numerous lymph 

 follicles. The protractor muscles arise in the xiphoid region and decussate pos- 

 teriorly around the extremity of the penis. 



The pelvic part of the urethra is relatively long. Its first part is inclosed in 

 the prostate.^ At the ischial arch the urethra has a well-developed bilobed bulb, 

 formed by an enlargement here of the corpus spongiosum. It is covered by 

 the strong but short bulbo-cavernosus muscle. The other erectile bodies have 

 been described. 



The urethral (Wilson's) muscle is very strong; it encircler the urethra and 

 has a median raphe dorsally. 



' This is clinically important, since enlargement of the prostate may interfere with mic- 

 turition. 



