39 o DISCOVERY REPORTS 



immediately dorsal to the neck of the bladder (Fig. 8 d). Just lateral to the neck of the 

 bladder, after a very short and straight course, each common iliac artery divides 

 into two branches. The anterior branch is the hypogastric artery. This passes on 

 to the neck of the bladder, giving off some short rami to the bladder wall, and 

 ascends to the summit of the urinary bladder, where it becomes enclosed in a thick 

 muscular sheath, and with its homologue of the opposite side, forms the umbilical 

 artery in this region (Fig. 8 b). The other branch from the common iliac on each 

 side runs outwards and forwards over the floor of the abdominal cavity as the deep 

 epigastric artery (Fig. 8 c). Each deep epigastric ramifies among the ventral abdominal 

 muscles and anastomoses with the internal mammary system at its posterior termination. 

 On their course the epigastrics come into close relation with the attachments of the 

 genital cords to the abdominal parietes. They do not, however, pass through the vascular 

 foramen of the rectus abdominis muscle, as described by Schulte (1916). They pass in 

 front of and mesal to it. An artery leaves the epigastric on each side of the body and 

 passes backwards through the foramen of the rectus (Fig. 8 e). Immediately within 

 the foramen it splits into one or more branches to the pelvic musculature and a main 

 pudic artery (Fig. 8/, g). Murie (p. 269) believed that the trunk which shortly breaks 

 up into small arteries to the pelvic musculature represents the external iliac artery, and 

 that the trunk which gives off the pudic artery and the arteries to the cavernous crura 

 represents the internal iliacs. The pudic artery passes on to the bulbus penis, crossing 

 the mass of the ischio-cavernosus muscle, and runs along the posterior face of the penis, 

 with its homologue of the opposite side, to the terminal cone. At the base of the bulbus 

 the pudic arteries give off a plexus of small branches to the cavernous crura (Fig. 8 g). 



The spermatic arteries come off from the dorsal aorta in the region of the inferior 

 mesenteric at the level of the testis and lower pole of the kidney. They form a compli- 

 cated fine network within the coverings of the testis and epididymis. They have been 

 studied in detail by Beauregard and Boulart,who found that the most voluminous arteries 

 enter the testis at its posterior extremity. Others serve the tail of the epididymis and the 

 origin of the vas deferens. Others reach the epididymis at the union of the tail and head. 



With regard to the veins of the genital region a pudic vein (Fig. 8 p) accompanies the 

 corresponding artery along the posterior face of the penis, and after crossing the bulbus 

 in a manner similar to the artery, receives a plexus of small veins from the cavernous 

 crura. This vein is joined by others from the pelvic musculature and runs inwards 

 through the vascular foramen of the rectus abdominis muscle (Fig. 8 o) to join the 

 deep epigastric vein accompanying the artery of that name. Together they form an 

 iliac trunk joining the post-caval trunk of that side of the body. Large lumbar veins 

 from the lateral superficies of the lumbar and caudal region (Figs. 1 k 3 , 12 k 3 , 8 r) run 

 inwards under the attachments of the ischio-caudalis muscle to the ischium on each 

 side and join the iliac veins. There are small arteries with corresponding veins from 

 the iliacs to the prostate and the neck of the bladder. 



The arrangement of the blood vessels in the inguinal region is much obscured by a 

 great arterial and venous vascular plexus which fills the posterior angles of the 



