CONTENTS. XI Structure of the capillaries.—Capillaries defined,—their size—Form of the capillary network. - Vascularity of different parts. Have the minute vessels open mouths? Serous vessels; parts in which the existence of blood-vessels is doubtful. Have the capillaries membranous'parietes? 2. Circulation in the capillaries.—As viewed by the microscope. Degree of resistance offered to, and rate of the blood’s motion in the capillaries. The heart’s action the sole moving power. The red particles themselves are passive, and are not arrested in the capillaries. Circulation of the lymph globules in the capillaries. Vital turgescence. Effects of the application of different substances to the capillaries. Their state in inflammation. Influence of the nerves on the capillary circulation. Of the veins.—Auxiliaries of the venous circulation,—the valves,—the heart. Influence of respiration on the venous circu¬ lation. Effects of obstruction to the circulation in the veins. Arterial and venous plexuses. Erectile structures, • .... 206-245 Chap. V,—Of the action of the blood-vessels in the processes of absorption and exudation, a. Of absorption.—Proofs of absorption independent of the lymphatics and lacteals. Imbibition. Endosmosis. Time required for absorption by imbibi¬ tion into the capillaries. Mode of action of poisons. Passage of ingesta into the secretions. Matters absorbed must be in solution. The laws of endosmosis modi¬ fied in the animal body. Absorption by organic attraction. Absorption aided by the action of the heart. Influence of galvanism, of the nerves, and of plethora on imbibition. Changes produced by the vessels on the matters absorbed. Cutaneous absorption. Interstitial absorption. b. Of exhalation and exudation.—Exudation and exhalation from physical causes. The process during life modified by organic laws. Exudation of secretions. Sources of the globules of secretions, . 245-265 SECTION III.—Of the lymph and the lymphatic vessels. Chap. I.—Of the lymph.—Physical and chemical properties of lymph. Human lymph,—its microscopic characters. Lymph of the frog. Globules of the lymph. Colour of lymph and chyle. Globules of the chyle, . . . 265-269 Chap. II.—Of the mode of origin and structure of the lymphatic vessels.— Reticulated and cellular lymphatics. Have the lacteals open mouths? Structure of the intestinal villi and of intestinal mucous membrane. The absorbent glands. Structure of the absorbent vessels. Communication of the absorbents with the se¬ creting canals of glands, and with small veins. Terminations of the absorbents. Lymphatic hearts, ....... 269-276 Chap. III.—Of the functions of the absorbents:—Source of the lymph. 1. Of the absorption by the lymphatics and lacteals.—Proofs that these vessels absorb. Pecu¬ liarities of the lymphatic and lacteal absorption. Power by which it is effected. 2. Change effected by the lymphatic and lacteal vessels on their contents.—3. Motion of the lymph and chyle.—The moving power. Rate of motion of the lymph and chyle, ......... 276—281 BOOK III. OF THE CHEMICAL CHANGES PRODUCED IN THE ORGANIC FLUIDS. AND ORGANISED TEXTURES UNDER THE INFLUENCE OF THE VITAL LAWS. Purely chemical processes. Organic chemical processes—assimilation. SECTION I.—Of respiration. Chap. I.—Of respiration in general.—The Atmosphere, Respirable and irrespirable gases. Aquatic respiration. The respiratory movements. Volume of air respired. Necessity of respiration to different animals, .... 281-290 Chap. II.—Of the respiratory apparatus.—Different forms of the respiratory appara¬ tus. In invertebrate animals. In vertebrate animals, . . . 291-294 Chap. III.—Of the respiration of man and animals.—1. Of respiration in the air.— Changes produced in the air,—quantity of carbonic acid generated. Amount of oxygen consumed. Changes produced in the proportion of the nitrogen in the air by respiration. Respiration of cold-blooded animals. Comparison of the products of the respiration of cold and warm blooded animals. 2. Of respiration in the water.—Changes produced in the water by the respiration of fishes. Respiration of fishes by the skin,—in the air. 3. Of the respiration of the embryo of animals.— Respiration of the embryos of birds and insects, and of Mammalia. Blood of the foetus. The liquor amnios, ....... 294-301 Chap. IV.—Of the changes which the blood undergoes in the lungs.—Differences