TEE INTERNAL ILIAC ARTEIiJI >. 543 



mill-so backward and downward, accompanied by a satellite vein and nerve, 

 - hc\\( 11 the peritoneum ainl ilium in following the inferior border 

 of the internal obturator muscle, and finally insinuates itself beneath that 

 muscle to make its exit from the pelvis by creeping through the oval (obtu- 

 rator) foramen, after furnishing a constant vesical twig. Placed between the 

 external obturator muscle and the inferior face of the ischium, it separates 

 into several branches, the majority of which descend into the internal 

 crural and ischio-tibial muscles (long or external vastus, and the semi- 

 membranosis and semiteudinosis), anastomosing with the ultimate divisions 

 of the ischiatic and deep femoral arteries. Among these branches there 

 are two or three which go to the roots of the penis, and enter the erectile 

 tissue of the cavernous body ; one of them, more important than the others by 

 its volume, is designated the artery of the corpus cavernosum. 



ARTERY OF THE CORPUS CAVERNOSUM (Fig. 275, 20). This vessel 

 creeps on the inferior face of the ischium, backwards and inwards, reaches 

 the crus penis, and pierces it by several branches, after supplying some 

 muscular divisions and the posterior dorsal artery of the penis. 



The latter is situated on the dorsal margin of the penis, passes forward 

 between the two ligaments attaching that organ to the symphysis pubis, 

 and proceeds to anastomose with the posterior branch of the anterior dorsal 

 artery (Fig. 275, 21.) 



7. Hiaco-femoral Artery (Figs. 275, 18 ; 277, 9.) 



Noticed as one of the terminal branches of the pelvic trunk, the iliaco- 

 femoral artery only exists as a vessel of a certain volume in Solipeds. In 

 other animals, as in Man, it is merely an insignificant and innominate branch 

 of the obturator artery. It proceeds outside the tendon of the small psoas 

 muscle, between the iliacus and the neck of the ilium, which it passes round 

 obliquely, above the origin of the anterior rectus muscle, to descend on the 

 external side of the latter, and plunge into the mass of the patcllar muscles, 

 e.itering them between the anterior rectus and vastus extornus, after sending 

 out some branches to the psoas, gluteal, and muscles of the fascia lata. 



DIFFERENTIAL CHARACTERS OF THE INTERNAL ILIAC ARTERIES IN OTHER THAN 8OLIPED 



ANIMALP. 



1. Internal Iliac Arteries of Ruminants. 



The terminal extremity of the aorta, after giving off the external iliac arteries, 



bifun-ati > to constitute the pelvic trunk*, and in the angle of bifurcation throws out a 



large branch the tacra media from which emanate the arteries of the tail. 



i. i .\\vvi-r. is not the only important peculiarity to be noted in the disposition of the 



The internal iliac artery emits at ita origin a very short, out very large 



h. \vhieh divides to form the umbilical artery, and an enormous uterine artery, tl at 



supplant*, to a great extent, the utero-ovariuii artery ; it is then din . tid 1 .arkwards, on 



tin- internal face of the gn at i.-rhiatic ligament, CTOMOg tin direction of the lumbo-sacral 



pli-Mi*. In its course it furnishes branch.- r. .--milling the iliaro-mutrulnr, the <jlnt,nl, 



ami tin ifr),i'<itir, and is continued about the middle of the pelvi- by khefaiamai /</<//> 



. \\hieh t<-rmin:ites liy forming the dortal artery of the clilori*, after diMrilmting 



i-es to tin' nctmii and the gen i to-urinary organs lodged in tin- \ hie eavity. 



It \\ill be -in ii.'iu this description which refers only to female animals, but is 



easily applicable to males that no mention is made of an ilium-femoral or oofur<i/<r 



liecause these two vessels are entirely absent in the >'//../.. and the la.-t. 



In tin larger Ruminants, is yet in a very rudimentary Mate. l...th 



Mippl. in. -nt. d liy the deep femoral, whose dimensions are eouktarabla. Neither ia 



the Int, ml Menu or tubtacral artery described, as it is also wanting, its /'/</<///.- branch 



coming directly from the j>elvic trunk, and its coccygeal <livi*ion being supplied by the 



middle sacral nrt 



