THORAX AND ABDOMEN OF THE HORSE 173 



M. psoas major. 



M. psoas minor. 



lateral ventral sacro-coccygeal muscles are bundles of fibres which 

 fill the intervals between the transverse processes of the last sacral 

 and first coccygeal and succeeding vertebrge. 



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 vertebrse, each hypogastric artery pursues an oblique 



A. glutasa cranialis. A. pudenda interna. 



, N. pudendus. 



N. hsemorroidalis caudalis. 

 I A. glutsea caudalis. 

 I I Rectum. 



Seminal vesicle. 



Prostate. 



M. retractor penis. 

 M. sacrococcygeus 

 I ventralis lateralis. 



M. sphincter ani. 



circumflexa ilium \, 



profunda. 

 T. cu'aneus femoris 



lateralis. , 

 A. iliolumbalis 



N. femoralis. /' 



Left ureter. / 



A. iliaca externa. 



/ / 

 A. circvimflexa femoris lateralis. / ' 



A. obturatoria. / 



A. umbilicalis. / 



Ductus deferens 



bulbi urcthrae. 

 I Bulbo-urethral gland. 

 Dorsal nerve of penis. 



Urinary bladder. 

 J Left ureter. 

 Line of reflection of peritoneum. 



Fig. 76. — Lateral aspect of the pelvic 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 manner of 

 the other members of the series. 



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



