Physiology. — ''On. the infiueiire of the increase of the osmotic 

 pressure of the jluids of the hodi/ on (liferent cell-snJjsfrnta." 

 By Dr. S. dk Boer. (Comniiuiicated bj Prof. G. van Ri.inhkrk). 



(Gommuiiicated in the meeting of March 28, 1918.) 



In the following experiments an investigation was made inio the 

 influence of the increase of I he osmotic j)ressiire of (he (Inids of the 

 body on the vital functions of frogs. The increase of the osmotic 

 pressure was brought about along ditferent vvajs, which I intend to 

 indicate here successively, mentioning at the same lime the j)henomena 

 I observed. 



I. Frogs wei-e placed into a hyperisotonic solution of Rinokr 

 containing instead of 6.5 gr. (p. 1..) NaCI J 8 gr. NaCI. Such a 

 quantity of this fluid was poured into the vessel in which the 

 frogs had been removed, that the head and the back j)rojec(ed 

 above it. A considerable part of the surface of the skin was then 

 in contact with the hjqierisotonic solution of Ringeh. When the 

 frogs had remained in this solution for about 20 houi-s, they showed 

 a series of phenomena as a consequence of the increase of the 

 osmotic pressui-e of the fluids of the body. The first phenomenon 

 that is observed, is the coinatous condition. The frog sits still in a 

 squatting position with (he connective fleeces (meinl)ranes) before the 

 eyes, and no longer leaps about. If one stretches out a hindleg, 

 this abnoi-mal posture of the leg is indeed corrected again but very 

 sluggishly. After a longer residence in the hyperisotonic siiri-oundings 

 this correction does not take place. Irritations of the skin have a 

 slight rellectoric effect which in a later stage is likewise reduced to 



Fig. I 



