668 BLOOD-VASCULAR SYSTEM OF THE HORSE 
collateral branches are detached to the ureter, the epididymis, and the spermatic 
cord. 
Va. The utero-ovarian arteries in the female correspond to the preceding ves- 
sels, but are much larger and shorter. Each is placed in the anterior part of the 
broad ligament of the uterus and divides into ovarian and uterine branches. The 
ovarian artery (A. ovarica) pursues a flexuous course to the ovary, which it supplies. 
The anterior uterine artery (A. uterina cranialis) passes to the concave border of the 
cornu of the uterus, which it supplies, anastomosing with the middle uterine artery, 
VI. The lumbar arteries (Aa. lumbales) are in series with the intercostal 
Sacro-coccygeus ventralis 
PRecto-coccygeus 
Sphincter ani externus 
Retractor ant 
Perineal artery + 
Perineal nerves fii 
Internal pudic y 
artery 
Dorsal nerve of 
penis 
Fic. 577.—DIsseEcTION OF PERINEUM Or Horse (Mate), 
1, Bulbo-urethral gland; 2, transversus perinei muscle (?); 3, ischio-urethral muscle; 4, retractor penis muscle; 6, 
bulbo-cavernosus muscle. (After Schmaltz, Atlas d. Anat. d. Pferdes.) 
arteries and have a similar origin and distribution. There are usually six pairs of 
lumbar arteries, of which five arise from the aorta and the sixth from the internal 
iliae or the lateral sacral at the junction of the last lumbar vertebra and the sacrum. 
Hach passes across the body of a lumbar vertebra to the intertransverse space, 
gives branches to the sublumbar muscles, and divides into dorsal and ventral 
branches. The dorsal branch (Ramus dorsalis), the larger of the two, passes 
upward to ramify in the extensor muscles of the spine and the skin of the loins; 
it gives off a spinal branch (Ramus spinalis) which comports itself like the corre- 
sponding branch of an aortic intercostal artery. The ventral branch (Ramus 
ventralis) runs outward in the intertransverse space, passes between the transversus 
