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JANE I. EOBERTSON. 
arises from the dorsal aorta on the right side a short distance 
behind the point of junction of the two aortic roots. It 
passes first ventrally, then posteriorly, along the right outer 
angle of the liver, and crosses the ventral surface of that organ 
to reach the tip of the gall-bladder, dorsal to which it finally 
l eaches the intestine, in the wall of which it is distributed. 
Subclavian Arteries. — Two small vessels, the subclavian 
arteries (Text-fig. 2, ScL), arise one on either side of the aorta 
immediately posterior to the cceliac artery and pass outwards 
to supply the pectoral limbs. 
Anterior Mesenteric Artery. — This vessel (Text-fig. 2, 
A. mes.) arises from the mesial ventral surface of the dorsal 
aorta far back, a short distance in front of the iliac arteries, 
and passes in the mesentery to reach the walls of the intestine, 
to which it is distributed. 
Posterior Mesenteric Artery. — Immediately posterior 
to the anterior mesenteric artery a second vessel, the posterior 
mesenteric (Text-fig. 2, P. mes.), arises also from the mesial 
ventral surface of the dorsal aorta and passes through the 
mesentery to the intestine, to which it also is distributed. 
Iliac Arteries. — Posteriorly two small vessels (Text-fig. 
2, II. A.) arise from the dorsal aorta near its caudal extremity 
and are distributed, one on either side to the pelvic limbs. 
c. Veins. 
Ductus C u V i eri . — A short transverse ductus Cuvieri opens 
into the anterior part of the sinus venosns (Text-fig. 3, S. V.) 
on either side ; these vessels are formed by the junction of the 
anterior and posteiior cardinal veins (Text-fig. 3, r. D. C. and 
l.D. C.). 
Anterior Cardinal Veins. — On each side an anterior 
cardinal vein (Text-fig. 3, A. Car.) passes back superficially 
from the front of the upper jaw, receiving an anterior cerebral 
vein in front of, and an orbital vein immediately behind, the 
eye, beneath which organ it passes : it also receives a vessel 
from the surface of the lower jaw at the angle of the mouth. 
Posteriorly a venous trunk, the posterior cerebral vein (Text- 
