THE POSTERIOR AORTA. 535 



UTERO-OVARIAN ARTERY. The origin of this vessel is conformable with 

 that of the preceding artery. It is placed between the two laminae of the 

 broad ligament, and soon bifurcates into the ovarian and uterine arteries. The 

 ovarian branch describes numerous flexuosities, like the corresponding artery 

 in the male, and comports itself on the ovary in the same manner as the 

 latter vessel does on the testicule. The uterine branch passes to the cornu 

 of the uterus, where its divisions anastomose with the proper uterine artery. 



7. Small Testicular Arteries : Male. Uterine Arteries : Female. 



SMALL TESTICULAR ARTERY (CREMASTERIC ARTERY, ARTERY OF THE 

 CORD). A pair, like the great testicular artery, this vessel is very slender, 

 and originates either from the aorta between the internal and external iliacs, 

 or from the latter, near its commencement. The last being the most 

 common, it is usual to describe it as a collateral branch of the crural (external 

 iliac) trunk. We have regarded it as an artery emanating directly from 

 the posterior aorta, in order to include its description with that of the great 

 testicular and the utero-ovarian arteries. 



Whatever may be its mode of origin, it gains the entrance to the vaginal 

 sheath, and enters it with the spermatic vessels, to be distributed to the 

 various parts constituting the cord. Before penetrating the substance of this 

 cord, it gives off several ramuscules destined for the peritoneum, iliac glands, 

 ureter, and deferent canal. 



UTERINE ARTERY. This has the same point of origin as the preceding, 

 its analogue, but differs from it in its larger volume. It is placed between 

 the two layers of the lumbar ligament, and is divided into two branches on 

 arriving at the small curvature of the uterine cornu : the anterior branch 

 anastomoses by its divisions with the utero-ovarian artery ; the posterior 

 passes to the body of the matrix, where it communicates with the vaginal 

 artery. 



DIFFERENTIAL CHARACTERS OF THE POSTERIOR AORTA AND ITS COLLATERAL BRANCHES IN 

 OTHER THAN SOLIPED ANIMALS. 



1. Posterior Aorta in Ruminants. 



The artery pursues the same course as in Solipeds, and also terminates by four 

 branches, towards the entrance to the pelvic cavity. 



PARIETAL BRANCHES. The intercostal arteries only differ from those of the Horse in 

 their number ; as but twelve are met with, of which eight or nine alone are furnished by 

 the posterior aorta. 



The lumbar and diaphragmatic branches are absolutely identical, in their disposition, 

 with the analogous arteries of Solipeds. 



The middle sacral artery is more considerable in volume, particularly in the Sheep 

 and Goat. This will be referred to hereafter (see internal iliac artery of Kuminants). 



VISCERAL BRANCHES. Broncho-cesophageal trunk. This offers nothing particular. 



Cceliac trunk (Fig. 273, 1). This artery descends on the rumen, a little behind the 

 insertion of the oesophagus, is directed to the right, and divides near the omasum into 

 two terminal branches the superior and inferior arteries of the omasum and abomasum. 



The collateral branches escaping from this trunk are : 



1. Several diaphragmatic arteries. 



2. The splenic artery, almost exclusively destined for the spleen (Fig. 273, 8). 



3. The superior artery of the rumen, always arising from a very short trunk common 

 to it and the preceding vessel, is carried backward to the superior face of the rumen, and 

 from this descends between the two conical vesicse to anastomose with the artery of the 

 inferior face of the viscus (Fig. 273, 2). 



4. The inferior artery of the rumen, which is insinuated between the two anterior 

 culs-de-sac, and afterwards runs along the inferior face of the organ, passing towards 

 the notch separating the two conical vesicse, to meet the superior vessel fFig. 273, 3). 



