Lymphatics and lacteals are furnished with valves serving the same office as those of the veins, and for the most part constructed after the same fashion. Lymph and chyle, unlike the blood, pass 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. In some part of their course all lymphatic vessels pass through certain bodies called lymphatic glands. Analysis of lymph and chyle: Lymph. Lymph from Chyle from Thoracic Duct. the Lacteals. Water, 937.32 939.70 902.37 Fibrine, 0.595 10.60 3.70 Albumen, 42.775 38.83 35.16 Fat, 6.51 a little 36.01 Extractive Matter, 5.05 Salts, 7.75 10.87 22.76 ------ ------- ------- 1000. 1000. 1000. Chyle having reached the lymphatic channels, its onward progress is determined by a variety of circumstances. Putting aside the pumping action of the villi, the same events which cause the movement of the lymph generally, also further the flow of the chyle, and these are briefly as follows: 1. The wide-spread presence of valves in the lymphatic vessels causes every pressure exercised on the tissues in which they lie, to assist in the propulsion forward of the lymph. 2. Considering the whole lymphatic system as a set of branching tubes passing from the extravascular regions just outside the small arteries and veins and capillaries, to the large venous trunks, it is obvious that the mean pressure of the blood in the subclavian at the junction with the jugular is the cause of the movement, etc., assisted perhaps by the respiratory movements, and other causes, as osmosis, etc. The average quantity of solid fecal matter evacuated by the human adult in twenty-four hours is about five ounces; an uncertain proportion of which consists simply of the undigested or chemically modified residue of the food, and the remainder of certain matters which are excreted in the intestinal canal. Gases contained in the stomach and intestines. The sources of the gases contained in the stomach and bowels may be enumerated: 1. Air introduced in the act of swallowing either food or saliva. 2. Gas developed by the decomposition of alimentary matter, or of the secretions and excretions mingled with it in the stomach and intestines. 3. It is probable that a certain mutual interchange occurs between the gases contained in the alimentary canal, and those present in the blood of the gastric and intestinal blood-vessels.