204 MANUAL OF PHYSIOLOGY. 



aid of the direct activity of cells which by amoeboid movement 

 take up the fine particles and pass them on to the interstices of 

 the connective tissue of the villi. 



LYMPH AND CHYLE. 



As these two fluids are mixed together in the thoracic duct, 

 whence the lymph is commonly obtained for examination, they 

 had better be considered at the same time. 



As we should expect, the fluids coming from the tissue drain- 

 age, from the lymphatic glands, and from the lacteals of the 

 alimentary tract form an opaque mixture which holds a consider- 

 able quantity of proteid in solutipn, and contains a number of 

 morphological elements, viz.: (1), protoplasmic cells similar to 

 those found in the lymph follicles, and in most essential points 

 identical with the pale cells found in the blood ; (2), some red 

 blood corpuscles which give the fluid in the thoracic duct a 

 pinkish color ; (3), a quantity of very finely divided fat, which 

 varies in proportion to the amount of fat recently digested ; (4), 

 other minute particles of unknown function and origin. 



When removed from the body and allowed to stand, the lymph 

 becomes converted into a soft jelly. This coagulation no doubt 

 depends upon chemical changes in the lymph which give rise to 

 fibrin. This subject will be discussed more fully in a future 

 chapter. The amount of fibrin formed in the lymph is very 

 small, and therefore the clot is very soft and shrinks considerably. 

 The quantity of chyle which can be obtained from the lacteals is 

 also small, and therefore the thorough investigation of it is diffi- 

 cult. The fluid from the tissues differs from the mixed lymph in 

 appearance and constitution only during digestion, and then 

 chiefly in containing a greater amount of fat and solids derived 

 from the intestinal cavity. The lymph of the thoracic duct con- 

 tains three forms of proteid : (1), serum albumin, which can be 

 coagulated by heat ; (2), alkali albumin precipitated by neutral- 

 ization ; and (3), globulin. It also contains in solution soap, 

 cholesterin, grape-sugar, urea, leucin, and some salts, particu- 

 larly sodium chloride, and the sulphates and phosphates of the 

 alkalies. 



