THE LYMPH. 359 



a stimulating effect upon the cells of the tissues and cause an 

 absorption of cellular water. The latter, on the other hand, are in 

 part unknown substances which can be extracted from the muscles 

 of the crab, from the head and body of leeches, from the bodies of 

 anodonts, from the liver and intestines of the dog, and also com- 

 prise the peptones and egg-albumin. The influence of these sub- 

 stances is apparently exerted upon the endothelial cells of the 

 blood-capillaries, whereby the secretory power is increased, and 

 we accordingly find more albumin in the lymph than in the remain- 

 ing blood-plasma. Such lymph then, in contradistinction to the 

 cellular lymph which is found in the first instance, may be termed 

 blood-lymph. The state of the blood-pressure, according to Heiden- 

 hain, is of no moment in bringing about these changes, and he found, 

 as a matter of fact, that variations between 10 and 20 Hgmm. on the 

 one hand, and 150 to 200 Hgmm. on the other hand, are of little 

 influence upon the amount of lymph that is produced. This view, 

 however, is in all probability not final. 



According to Bunge, the amount of lymph that is formed in the 

 twenty-four hours by the human being amounts to about 4000 c.c. 



A general idea of the chemical composition of lymph may be 

 formed from the following analysis of Munck and Rosenstein. 

 The material was obtained from a fistula in the thigh of a young 

 woman. Accompanying this is an analysis of the blood-plasma 

 (taken from Hammarsten) for comparison : 



Lymph. Blood-plasma. 



Water 96.5 -94.5 per cent. 91.8 per cent. 



Solids 3.7 -5.5 



Albumins 3.4 -4.1 



Ethereal extract 0.06 -0.13 



Sugar 0.1 



Salts 0.8 -0.9 



Sodium chloride . . . 0.55 -0.58 



Sodium carbonate . . 0.24 



Disodic phosphate . . 0.028 



8.2 



0.46 " 

 0.84 " 



Of these constituents, the fat is subject to the greatest variations, 

 and is, of course, always more abundant during the process of diges- 

 tion in the chyle than in any other lymphatic district. In Munck's 

 case the amount rose to 4.7 per cent, after the ingestion of a large 

 amount of fatty food, and decreased to 0.06-0.26 per cent, when 

 food was withheld for twenty-four hours. 



The fat is present in the lymph to the greatest extent as neutral 

 fat, and it is to be noted that it here exists in a state of emulsion, so 

 that upon microscopical examination the chyle more especially will 

 be seen to contain innumerable fat droplets, which vary but little in 

 size and have no tendency to flow together, as in the case of milk. 

 Why this is we do not know, but it has been suggested that each 

 fat droplet is surrounded by a delicate albuminous envelope, which 

 is derived from the normal albumins of the lymph. On the other 

 hand, it is conceivable that the surface layer of each droplet con- 



