AN EXPERIMENTAL ANALYSIS OP OEDEMA 37 



in these cases to determine in red-leg disease the effect of 

 albuminuria on the efficiency of the kidneys. 



In order to test the efficiency of the kidneys in frogs which 

 are not afflicted with red-leg disease, but in which an acute 

 nephritis had been developed, the following procedure was 

 adopted : 



Normal frogs were transferred alternately to and fro from 

 water at room temperature to water at 38° C, until an acute 

 nephritis had been developed with albumin and abundant 

 casts showing in the urine. The nephritis apparently resulted 

 from an overfunctioning of the kidneys. This procedure 

 often required several days, and in order not to kill the frog 

 during the experiment, the writer immediately revived a frog 

 as soon as it appeared sluggish or slightly comatose by plac- 

 ing it in water at a much lower temperature. In table 11 we 

 have the behavior of such a frog, which was placed first in 

 water at 29° and later in water at 16 °G. During the twenty 

 hours that the frog was in water at 29° and 16°C, there was 

 no gain in weight of any significance; obviously, the albu- 

 minuria did not cause any inefficiency in kidney functioning, 

 as a normal balance was maintained in the body between the 

 incoming and outgoing water. 4 



SUMMAEY 



Oedema, both localized and generalized, manifests itself in 

 red-leg disease in two forms which we may designate as 

 subcutaneous and intracellular (interstitial?) oedema. 



A localized and excessive accumulation of lymph in the 

 subcutaneous lymph sinuses results from a local block in the 

 efferent drainage channels. As water is being constantly 

 driven by osmosis through the integument into the subcutane- 

 ous lymph sinuses, lymph gradually accumulates in the latter, 

 distal to the block and locally in the sinuses. The osmotic- 

 pressure of this oedematous lymph is lower than that of 

 normal resting muscle. 



* I wish to express my thanks and appreciation to my colleague, Prof. E. Newton 

 Harvey, for the many favors extended to me during the course of this inves- 

 tigation; my thanks are also due Mr. W. P. Agnew for his kindness in preparing 

 the photographs for me. 



