BLOOD-VASCULAR SYSTEM OF THE LORICATI 67 
Quite an important vessel arises from the right side of the 
coeliac artery shortly before it separates to form the pyloric caca 
arteries, or sometimes it may arise from the right pyloric ceca 
artery; it is the vessel designated as zntestznal artery,,, (Pl. I, 
figs. 1, 6 and 11; Int.A..)), which strikes the intestine about 
mid-way between the pylorus and the rectum. For a short 
distance it runs along, inclosed in adipose tissue, just dorsad of 
the intestine, and crossing over to the ventral side of the intes- 
tine, exchanges places with intestinal artery,,. This vessel is 
distinctly a posterior intestinal artery and usually extends to 
the rectum. Throughout its entire course it sends off branches 
to the muscular walls of the intestine, which break up into a 
capillary network in the connective tissue layer of the crypts. 
In the region of the liver several small branches from the ce- 
liac are given off to the anterior part of the intestine. 
(6) Mesenteric Artery (Pl. I, fig.1; Mes.A.). — This vessel 
is destined to supply the spleen, the greater part of the stomach, 
and intestine. Soonafter leaving the cceliaco-mesenteric trunk 
the mesenteric artery gives off the /e/¢ gastric artery (P1. 1, figs. 
1 and 6; L.Gas.A.) to the left and ventral side of the stomach. 
This vessel, which lies above the corresponding vein and left 
gastric ramus of the vagus nerve, crosses the stomach at right 
angles, then passing along the left side of the stomach, gives 
off branches to either side, which soon penetrate the muscular 
walls and break up into a capillary network in the connective 
tissue layer of the crypts. The main mesenteric trunk after 
following the stomach for a short distance bifurcates into the 
right gastric, and intestinal artery,,. The rzght gastric artery 
(fig. 1; R.Gas.A.), which is considerably larger than the left, 
continues between the right gastric ramus of the vagus nerve 
and the right gastric vein to the posterior or cardiac portion of 
the stomach, giving off branches from either side to the mus- 
cular walls of the stomach. Close to its origin it sends off a 
branch to the right (see fig. 1), which crosses the cceliac artery 
and the right portal vein to a gland-like body (G. fig. 1) situ- 
ated at the junction of the right gastric and the intestinal veins 
(in structure this gland is very much like the suprarenal bodies). 
ihe /ntesinalantery i Pil, hes.) Band) Ose into...) pur 
