334 CHYLE, LYMPH, TRANSUDATES AND EXUDATES. 



are alone sufficient to explain the lymph formation (COHNSTEIN, ELLINGER) 

 remains an open and disputed question. 1 



II. TRANSUDATES AND EXUDATES. 



The serous membranes are normally kept moistened by liquids whose 

 quantity is sufficient only in a few instances, as in the pericardial cavity 

 and the subarachnoidal space, for a complete chemical analysis to be made 

 of them. Under diseased conditions an abundant transudation may 

 take place from the blood into the serous cavities, into the subcutaneous 

 tissues, or under the epidermis ; and in this way pathological transudates 

 are formed. Such true transudates, which are similar to lymph, are 

 generally poor in form-elements and leucocytes, and yield only very little 

 or almost no fibrin, while the inflammatory transudates, the so-called 

 exudates, are generally rich in leucocytes and yield proportionally more 

 fibrin. As a rule, the richer a transudate is in leucocytes the closer it 

 stands to pus, while a diminished quantity of leucocytes renders it more 

 nearly like a real transudate or lymph. 



It is ordinarily accepted that filtration is of the greatest importance 

 in the formation of transudates and exudates. The facts coincide "with 

 this view that all these fluids contain the salts and extractive bodies 

 occurring in the blood -plasma in about the same quantity as the blood- 

 plasma, while the amount of proteins is habitually smaller. While the 

 different fluids belonging to this group have about the same quantities 

 of salts and extractive bodies, they differ from one another chiefly in 

 containing differing quantities of protein and form-elements, as well as 

 varying quantities of transformation and decomposition products of 

 these latter changed blood-coloring matters, cholesterin, etc. The 

 correspondence in the amount of salts and extractive bodies present in 

 the blood and in transudates supplies just as little proof for a filtration 

 as it does for the formation of lymph; but still it cannot be doubted for 

 other reasons that filtration is often of great importance in the formation 

 of a transudate. To what extent filtration is active in the perfectly 

 normal vascular wall cannot be answered. 



The altered permeability of the capillary walls in disease is a second 

 important factor in the formation of transudates. The circumstance 

 that the greatest quantity of protein occurs in transudates in inflammatory 

 processes, to which is also due the abundant quantity of form-elements 

 in such transudates, has been explained by this hypothesis. The greater 

 quantity of protein in the transudates in formative irritation is in great 

 part explained by the large amount of destroyed form-elements. The 



1 On this question see Ellinger, " Bie Bildung der Lymphe," Ergebnisse der Phy- 

 siologic, I, Abt. 1, 355, and Asher, Biochem. Centralbl., 4, pp. 1 and 45. 



