THORAX AND ABDOMEN OF THE HORSE 173 



lateral veotral sacro-coccygeal muscles are bundles of fibres which 

 fill the intervals between the transverse processes of the last sacral 

 and first coccygeal and succeeding vertebrae. 



A. HYPOGASTRICA. — The hypogastric arteries, right and left, form 

 two of the four terminal branches of the abdominal aorta. Leaving 

 the aorta on a level with the joint between the bodies of the fifth 

 and sixth lumbar vertebrje, each hypogastric artery pursues an oblique 



A. glutaea cranialis. A. pudenda interna. 



' , N. pudendus. 



M. psoas major 



M. psoas minor 



N. haemorroidalis caudalis. 

 A. glutsea caudalis. 

 turn. 

 Seminal vesicle. 

 Prostate. 



M. retractor penis. 

 M. sacrococcygeus 

 ventralis laterahs. 

 M. sphincter an 



K. circumflexa ilium ^^ /. 

 profunda. */ 

 N. cu'aneus femoris 



lateralis. , 

 A. iliolumhalis 



N. femoralis. 



Left ureter. 

 A. iliaca externa. /' / 

 A. circumflexa femoris lateralis. /' 



A. obturatoria. / 

 A. umbilicalis. / 

 Ductus deferens 



A. bulbi urethrse. 

 Bulbo-urethral gland. 

 Dorsal nerve of penis. 



Urinary bladder. 

 J Left ureter. 

 Line of reflection of peritoneum. 



Fig. 76. — Lateral aspect of the jjelvic vessels, nerves and organs of the male, after 

 removal of the hip-bone. The position of the bone is indicated by 

 the strong dotted line. 



lateral and caudal course ventral to the transverse process of the 

 first sacral vertebra and the articulation between this and the ilium. 

 At the sacro-iliac joint, or slightly beyond it, the vessel divides into 

 three arteries — ilio-lumbar, cranial gluteal and obturator. 



The following are the branches of the hypogastric artery : — 



(1) Close to its origin from the aorta the hypogastric furnishes 

 the sixth lumbar artery, which conducts itself after the tuanner of 

 the other members of the series. 



(2) A. pudenda interna. — The internal pudendal artery is also 



