ABSORPTION. 413 



(fig. 276). The fluid which they contain, unlike the blood, passes only 

 in one direction, namely, from the fine branches to the trunk and so to 

 the large veins, on entering which they are mingled with the stream of 

 blood and form part of its constituents. The course of the fluid in the 

 lymphatic vessels is always toward the large veins in the neighborhood 

 of the heart, and in fig. 276 the greater part of the contents of the lym- 



Fig. 277. Fig. 278 



Fig. 277. Superficial lymphatics of right groin and upper part of thigh, .1. Upper inguinal 

 glands. 2,2'. Lower or inguinal or femoral glands. 3, 3'. Plexus of lymphatics in the course of the 

 Tong saphenous vein. (Mascagni.) 



Fig. 278. Lymphatic vessels of the head and neck and the upper part of the trunk (Mascagni). 

 . The chest and pericardium have been opened on the left side, and the left mamma detached and 

 thrown outward over the left arm, so as to expose a great part of its deep surface. The principal 

 lymphatic vessels and glands are shown on the side of the head and face, and in the neck, axilla, 

 and mediastinum. Between the left internal jugular vein and the common carotid artery, the upper 

 ascending part of the thoracic duct marked i, and above this, and descending to 2, the arch and last 

 part of the duct. The termination of the upper lymphatics of the diaphragm in the mediastinal 

 glands, as well as the cardiac and the deep mammary lymphatics, is also shown. 



phatic system of vessels will be seen to pass through a comparatively 

 large trunk called the thoracic duct, which finally empties its contents 

 into the blood-stream, at the junction of the internal jugular and sub- 

 clavian veins of the left side. There is a smaller duct on the right side. 

 The lymphatic vessels of the intestinal canal are called lacteals, because 

 during digestion the fluid contained in them resembles milk in appear- 



