22 CHABLES P. W. MC CLURE 



correspondingly diminished, so that through the agency of 

 the vascular system less water reaches the kidneys than simul- 

 taneously enters the body through the integument. Such con- 

 ditions obtain when frogs are subjected to these high tem- 

 peratures; since, however, frogs are unable for any extended 

 period to endure them, an actual oedematous condition of the 

 body cannot be experimentally produced in the living frog 

 by thus increasing the temperature of the water. 



Under natural conditions of environment, however, 

 oedematous frogs with red-leg disease do continue to live a 

 considerable time after cardiac inefficiency is manifest. The 

 writer will show later that this inefficiency prevents the estab- 

 lishment of the normal balance between the incoming and 

 outgoing flow of water, and so is itself a contributing factor 

 of the oedema. Moreover, dead frogs, when placed in water 

 at any temperature, gain weight continuously through a con- 

 siderable period of time. This is because though after death 

 water continues to be transported in the usual manner 

 through the integument, this water, owing to a complete cessa- 

 tion of circulation, cannot be transported to the kidneys. 

 These two observations indicate the relation that exists be- 

 tween cardiac inefficiency and oedema. 



A brief resume of the chief observations made in the pre- 

 ceding pages leads us to the following conclusions : 



1. Oedema manifests itself in the frog in two forms which 

 we may distinguish as subcutaneous and intracellular (inter- 

 stitial?). 



2. Any factor, either local or general, which may prevent 

 the establishment of a normal balance between the incoming 

 and outgoing flow of water, such as a deficiency in the develop- 

 ment of the kidneys, ligation of a limb, ligation of the ureters, 

 or cardiac inefficiency, will serve as a contributing cause of 

 oedema. 



3. Subcutaneous oedema is an excessive accumulation of 

 lymph in the subcutaneous lymph sinuses and is invariably 

 accompanied by an intracellular (interstitial?) oedema or 

 swelling of the tissues, which results from differences in os- 



