330 THE ANATOMY OF THE HORSE. 



the following course. Beginning at the hilus, it is directed backwards 

 and inwards across the lower face of the kidney to place itself at the 

 side of the aorta, over (under, in the natural position) the psoas parvus 

 muscle. Here it is crossed obliquely by the spermatic artery. It next 

 curves a little outwards, crossing over the circumflex iliac artery, and 

 the artery of the cord, runs at the outer side of the external iliac 

 artery, and then crosses it very obliquely to enter the pelvis. The 

 right ureter has similar relations, except that it passes at the side 

 of the vena cava instead of the aorta. 



Directions. — Pin each ureter in position immediately behind the 

 kidney, and then cut it across. Remove carefully the liver, stomach 

 duodenum, spleen, pancreas, and kidneys, by cutting the oesophagus 

 and the various ligaments, vessels, and cellular adhesions which retain 

 these organs in position. Put them in preservative solution, or procure 

 fresh organs, to serve for the examination of their structure. In the 

 meantime proceed to dissect the sublumbar region. 



THE SUBLUMBAR REGION. 



Directions. — Under this heading there will be described the abdominal 

 aorta and the vena cava, with their branches ; the inferior primary 

 branch of the last dorsal nerve, and the corresponding branches of the 

 first four lumbar nerves ; the aortic plexus and gangliated lumbar cord 

 of the sympathetic nerve ; and, lastly, a group of muscles, comprising 

 the iliacus, psoas magnus, psoas parvus, quadratus lumborum, and 

 lumbar intertransverse muscles. The great arterial and venous trunks 

 are mesially placed, and the aortic plexus is on the great artery. The 

 other structures enumerated are the same on both sides of the body. 

 One side may be used for the nerves and the arterial and venous 

 branches, the other being reserved for the muscles. In the mare, 

 after the ovarian and uterine vessels have been examined, the broad 

 ligaments must be cut to allow of the ovaries and uterus being 

 pushed into the pelvic cavity, where they are to remain until they 

 can be dissected along with the other reproductive organs of the 

 female. 



Lymphatic Glands. In cleaning the nerves and vessels, the follow- 

 ing groups of lymphatic glands will be found: 1. Sacral glands, 

 between the right and left internal iliac arteries at the entrance to the 

 pelvis. 2. Internal Iliac glands, between and around the roots of the 

 external and internal iliac arteries on each side. 3. External Iliac 

 glands towards the point of bifurcation of the circumflex iliac artery. 

 4. Lumbar glands, on the lower face of the aorta around the roots of 

 the posterior mesenteric and spermatic arteries. These various groups 

 of glands are placed on the course of the lymphatic vessels of the hind 



