The anterior division of the femoral lymphatic trunk accompanies the aorta, on which it forms a plexus with the branches of the opposite side, and with the intestinal lymph vessels. These vessels commence from a continuous plexiform network located between the mucous and the muscular coat of the intestine. They are larger at this point than where they leave the intestine to pass through the mesentery. They accompany the trunk of the anterior mesenteric artery and form a plexus around it. Before reaching the region of the aorta, the intestinal lymphatic vessels communicate with the posterior division of the femoral trunk and with the lymph vessels of the ovary or of the testis. After passing to the region of the aorta they receive vessels from the pancreas and the duodenum, and terminate around the celiac axis with the lymphatics of the liver, the proventriculus, the gizzard, and the spleen, forming a rather voluminous plexus (Lauth). The aortic plexus represents the receptaculum chyli and gives origin to two thoracic ducts, mentioned above, which passing on each side of the bodies of the vertebræ, pass one right and one left, over the lungs, from which they receive lymph vessels, and terminate after receiving the lymph vessels of the wing, into the jugular vein of their respective sides. The left thoracic duct, before emptying into the vein, receives the trunk of the lymphatics of the left side of the neck, and the right duct that of the right side of the neck, each tributary collecting lymph from all the structures of its side. The lymphatics of the wing follow the course of the brachial artery, forming a plexus around it. These vessels are well developed in the elbow region. The principal trunk, following the humerus, receives collateral branches in its upper third. This vessel, when nearing the chest, receives two or three large lymph vessels from the pectoral muscles, and a branch which accompanies the brachial plexus. The lymph vessels of the head accompany the branches of the jugular vein, collecting the lymph from the structures of the head and the neck. The lymphatic vessels communicate at the anterior and posterior oblique anastomosing vessels. At the lower part of the neck each trunk receives a vessel, which accompanies the carotid arteries. Further on they are provided with a lymph gland which rests on the jugular vein. THE BLOOD AND ITS FUNCTIONS The special function of the blood is to nourish all the tissues of the body, and in this way to aid growth and repair. It furnishes material for the purpose of the elaboration of body secretions; it supplies the organism with oxygen; and it carries away carbon dioxid and other effete material. Blood is constantly in circulation.