626 CIRCULATORY SYSTEM OF THE PIG 



of the base of the udder; two large glands which are in apposition with each other 

 medially are constant, and above these there are often two smaller glands. 



An ischiatic lymph gland, which is discoid and usually about an inch in diam- 

 eter, is situated on the lower part of the sacro-sciatic ligament near the lesser sciatic 

 notch under cover of the biceps femoris. 



An anal lymph gland is situated on the retractor ani on either side. 



The gastric lymph glands are numerous and comprise: (1) a chain along the 

 course of the right ruminal artery and two or three in the left groove of the rumen; 

 (2) several on the reticulum above and below the junction with the omasum; (3) 

 a series along the course of the superior omasal vessels and the lesser curvature of 

 the abomasum; (4) an extensive chain along the ventral face of the omasum and 

 the great curvature of the abomasum at the attachment of the great omentum. 



Two or three large hepatic or portal lymph glands are found at the upper part 

 of the portal fissure of the liver. 



No lymph glands occur at the hilus of the spleen. The efferent vessels from 

 the spleen appear to go to glands along the course of the coeliac artery. 



A large discoid cceliac lymph gland lies on the pancreas and the coi'liac arterj^, 

 covering the latter as it gives olf its primary branches. 



The mesenteric lymph glands are large and numerous. They form a chain in 

 the lower part of the mesentery along the course of the great mesenteric artery. 

 They are chiefly elongated and narrow, and some have a length of six to eight inches 

 (15 to 20 cm.) or more. Sometimes several unite and form a narrow band about 

 two feet in length. A large gland occurs at the origin of the spiral part of the colon, 

 a group is found near the anterior mesenteric trunk, and others are scattered along 

 the coils of the colon, which are best seen on the right side. A chain of small 

 lymph glands extends along the terminal part of the colon and the dorsal face of the 

 rectum. 



The precrural lymph gland is situated on the aponeurosis of the external oblique 

 at the anterior jjorder of the tensor fasciae latse a short distance above the stifle. 

 It is elongated like the prescapular gland and may be six inches (ca. 15 cm.) long. 

 Several subcutaneous hsemolymph glands occur in this vicinity; others are situated 

 further forward on the flank not far from the last ril). There is usually a round, 

 flattened lymph gland about an inch in diameter on the upper part of the quadriceps 

 femoris under cover of the tensor fascise latae, and one or more small ones occur on 

 the surface of the latter muscle. 



No deep inguinal lymph glands are present. 



A single popliteal lymph gland an inch or more in length is situated somewhat 

 lower down on the gastrocnemius than in the horse, behind the tibial and peroneal 

 nerves. 



CIRCULATORY SYSTEM OF THE PIG 



THE HEART 



The pericardium is attached to the sternum from a point opposite to the third 

 rib as far as the xiplioid cartilage, and also to the sternal part of the diaphragm. 



The heart is small in proportion to the body-weight, especially in fat animals. 

 It is relatively short and wide. The apex is blunt and is marked b}' a notch (In- 

 cisura apicis). Its long axis is more oblique, but it is less asymmetrical with regard 

 to the median plane, than in the horse or ox. The lower border of the left auricle 

 (appendix) is marked by several notches and is situated at a lower level than the 



