418 ABSORPTION OF PARENCHYMATOUS EFFUSIONS. 



exclusively, upon the spinal cord, for if the cord be rapidly destroyed, they may 

 cease to pulsate (Volkmann), but not unfrequently they continue to pulsate after 

 removal of the cord (Valentin, Luchsinger). A second source of their pulsatile 

 movements is to be sought for in Waldeyer's ganglia. Stimulation of the skin, 

 intestine, or blood-heart influences them reflexly partly accelerating and partly 

 retarding them. If the coccygeal nerve, which connects the sacral hearts to 

 the spinal cord, be divided, these effects do not occur (v. Wittich). Strychnia 

 accelerates their movements (Scherhej). Antiar paralyses the lymph-heart and 

 the blood-heart at the same time (Vintschgau), while curara paralyses the former 

 alone (Bidder). 



In other amphibians, there are two lymph-hearts, in the ostrich and cassowary 

 and some swimming birds (Panizza), and in the embryo chick (A. Budge). They 

 occur in some fishes e.g., near the caudal vein of the eel. 



(7.) The nervoiis system has a direct effect upon the lymph-stream, 

 on account of its connection with the muscles of the lymphatics and 

 lymph-glands, and with the lymph-hearts where these exist. Farther, 

 Kiihne observed that the cornea-corpuscles contracted when the corneal 

 nerves were stimulated. Goltz also observed that when a dilute solu- 

 tion of common salt was injected under the skin of a frog, it was 

 rapidly absorbed, but if the central nervous system was destroyed it 

 was not absorbed. 



If inflammation be produced in the posterior extremities of a dog, and if the 

 sciatic nerve be divided on one side, oedema and a simultaneous increase of the 

 lymph-stream occur on that side (Jankowski). 



Ligatvire the leg of a frog, except the nerves, so as to arrest the circulation, and 

 place the leg in water; it swells up very rapidly, but a dead limb does not swell 

 up. So that absorption is independent of the continuance of the circulation. 

 Section of the sciatic nerve, or destruction of the spinal cord (but not section of 

 the brain), arrests absorption (Lautenbach). 



202. Absorption of Parenchymatous Effusions. 



Fluids which pass from the blood-vessels into the spaces in the tissues, or those 

 injected subcutaneously, are absorbed chiefly by the blood-vessels, but also by the 

 lymphatics. Small particles, as after tattooing with cinnabar or China ink, may 

 pass from the tissue-spaces into the lymphatics and so do blood- corpuscles from 

 extravasations of blood, and fat granules from the marrow of a broken bone. If 

 all the lymphatics of a part are ligatured, absorption takes place quite as rapidly 

 as before (Magendie); hence, absorbed fluid must pass through the thin membranes 

 of the blood-vessels. The corresponding experiment of ligaturing all the blood- 

 vessels, when no absorption of the parenchymatous juices takes place (Emmert, 

 Henle, v. Dusch), does not prove that the lymphatics are not concerned in absorp- 

 tion, for, after ligaturing the blood-vessels of a part, of course the formation of 

 lymph, and also the lymph-stream, must cease. 



When fluids are injected under the skin, absorption takes place very rapidly- 

 more rapidly than when the substance is given by the mouth. The subcutaneous 

 injection of many drugs is now extensively used, but of course the substances used 

 must not corrode, irritate, or coagulate the tissues. Some substances do not act 

 when given by the mouth, as snake poison, poisons from dead bodies or putrid 

 things, although they act rapidly when introduced subcutaneously. If emulsin be 

 given by the mouth, and amygdalin be injected into the veins of an animal, hydro- 



