274 Ititroduction [Dec. 



through the System of tissue Spaces. When the impediment of the 

 circulation is too great and the system of tissue Spaces becomes 

 overloaded with lymph, we have then the picture of general edema 

 and anasarca." 



The appended summaries suggest the causes of edema as 

 Cohnstein and Starhng estimate them. These two summaries 

 emphasize the possibiHties in disturbed equiHbrium of the normal 

 forces in lymph production and removal, but they also suggest the 

 current views on the intimate relationship between the normal for- 

 mation of lymph and its pathological modifications in quality and 

 quantity.^ 



cohnstein's summary of the causes of edema 



I. Increase of intracapillary pressure. 

 IL Reduction of pressure within the tissues. 



III. Increase of permeability of the capillary wall. 



IV. Chemical changes in the blood plasma. 

 V. Chemical changes in the tissue fluids. 



VI. Disorders in the removal of the tissue fluids by the lymphatics. 

 VII. Disorders in the removal of the tissue fluids by the blood vessels. 



starling's summary of the causes of edema 



/. Factors causing increased transudation. 



A. Increased intracapillary pressure. 



(a) Venous obstruction. 



(b) Vasodilation. 



(c) Plethora. 



B. Increased permeability of vessel-walls. 



(a) Local injury by mechanical irritants. 

 Local injury by thermal irritants. 

 Local injury by chemical irritants. 



(b) Malnutrition. 



(c) General injury by circulating poisons (?). 



'The reader is referred to Meltzer's very complete critical review of the 

 " Physiologie and pathologic f actors concerned in the formation of edema." 

 Meltzer: Harrington Lectures on Edema (University of Buffalo, N. Y.). Amer- 

 ican Medicine, 1904, viii, pp. 19-23, 59-63, 151-155, and 191-199. The summaries 

 credited above to Cohnstein and Starling have been taken from Meltzer's splen- 

 did review. 



