CHAPTER VI. 

 CHYLE, LYMPH, TRANSUDATES AND EXUDATES. 



I. CHYLE AND LYMPH. 



THE lymph is at least in part the mediator in the exchange of con- 

 stituents between the blood and the tissues. The bodies necessary for 

 the nutrition of the tissues pass from the blood into the lymph, and the 

 tissues deliver water, salts, and products of metabolism to the lymph. 

 The lymph, therefore, originates partly from the blood and partly from 

 the tissues. From a purely theoretical standpoint one can, according 

 to HEIDEHAIN, differentiate between blood-lymph and tissue-lymph 

 according to origin. It is impossible at the present time to separate 

 completely that which comes from the one or the other source. 



The lymph formed in th6 different organs and tissues has a different 

 composition, and as the lymph is not obtained directly but only from the 

 large lymph vessels, hence the lymph that we use for investiga- 

 tions is generally a mixture, whose composition may vary under certain 

 conditions. The most easily obtained and best studied is the lymph 

 from the thoracic duct. In starving individuals this lymph, which is 

 called starvation lymph, does not essentially differ from other lymphs. 

 After fatty food the lymph, which is called digestion lymph or chyle, 

 differs from other lymphs by its great richness in very finely divided fat, 

 which gives it a milky appearance, and which has led to the old name 

 " lacteal fluid." 



Chemically the lymph is the same as plasma, and contains, at least 

 to a great extent, the same bodies. The observation of ASHER and BAR- 

 BERA, 1 that the lymph contains poisonous metabolic products, does 

 not contradict such an assumption, as no doubt these products are trans- 

 ferred to the blood with the lymph. Although the blood does not show 

 the same poisonous action as the lymph, still this can be explained by the 

 great dilution these bodies undergo in the blood, and the difference 

 between blood-plasma and lymph is no doubt of a quantitative nature. 

 This difference consists chiefly in that the lymph is poorer in proteins. 



1 Zeitschr. f . Biologie 36. 



345 



