The _Rectum_ is the terminus of the large intestine. The intestines are abundantly supplied with blood-vessels. The arteries of the small intestine are from fifteen to twenty in number. The large intestine is furnished with three arteries, called the _colic arteries_. The _ileo-colic artery_ sends branches to the lower part of the ileum, the head of the colon, and the appendix vermiformis. The _right colic artery_ forms arches, from which branches are distributed to the ascending colon. The _colica media_ separates into two branches, one of which is sent to the right portion of the transverse colon, the other to the left. In its course, the _superior hemorrhoidal artery_ divides into two branches, which enter the intestine from behind, and embrace it on all sides, almost to the anus. The _Thoracic Duct_ is the principal trunk of the absorbent system, and the canal through which much of the chyle and lymph is conveyed to the blood. It begins by a convergence and union of the lymphatics on the lumbar vertebræ, in front of the spinal column, then passes upward through the diaphragm to the lower part of the neck, thence curves forward and downward, opening into the subclavian vein near its junction with the left jugular vein, which leads to the heart. [Illustration: Fig. 32. _c, c_. Right and left subclavian veins. _b_. Inferior vena cava. _a_. Intestines. _d_. Entrance of the thoracic duct into the left subclavian vein. _4_. Mesenteric glands, through which the lacteals pass to the thoracic duct.] [Illustration: Fig. 33. The inferior surface of the liver. 1. Right lobe. 2. Left lobe. 3. Gall-bladder.]