THE LYMPHATIC SYSTEM 759 
duodenum and the duodenal angle (or head) of the pancreas. In most cases two 
glands occur on the right of the portal vein and further back along the mesenterie 
vein. Glands of variable size and number occur in the gastro-splenic part of the 
omentum along the splenic vein and its radicles. 
The mesenteric lymph glands consist chiefly of two elongated nodes which 
extend from the root of the mesentery of the jejuno-ileum along the course of the 
artery of the small intestine and the corresponding vein. 
The colic lymph glands comprise a variable number of nodes (5-8) in the meso- 
colon. One is at the origin of the ileo-cxeco-colic vein; a second one may be found 
here. One or two may be found in the transverse mesocolon and others (2-5) 
occur at the terminal part of the colon. 
The renal lymph glands, one on each side of the aorta, are in relation to the 
origin of the renal arteries; the right one is concealed by the vena cava. 
The superficial inguinal lymph glands are embedded in the fat about the ex- 
ternal inguinal ring in relation to the external pudic vessels. In the male they are 
related medially to the penis; in the female they are commonly termed supra- 
mammary on account of their relation to the base of the inguinal mammary glands. 
In the majority of cases two are present on each side, but there is often only one, 
and sometimes three occur on one side. 
The popliteal lymph gland is situated ina mass of fat on the gastrocnemius 
at the level of the stifle joint. It is between the biceps femoris and semitendinosus, 
but is more superficial than in the other animals, and hence is commonly palpable. 
It is oval and in large dogs may be nearly two inches (ca. 4.5 em.) long and more 
than an inch (ca. 3 em.) wide. 
