48 CHARLES F. W. MCCLUEE 



Ringer's solution (figs. 11, 12, and 13). In the following 

 experiments we show how the action of this force may be 

 modified by the presence or absence of K in the Ringer's 

 solution. 



Experiments 533 and 571 (fig. 22) 



The right and the left skin gloves of the same frog (R. pi- 

 piens with the outside of the skin turned outward, were filled, 

 respectively, with Ringer minus K and Ringer, both approxi- 

 mately isotonic with frog's blood, and were then suspended 

 in a hypertonic saline solution (N/7 NaCl). (See diagrams 

 I and J in fig. 22 for type of experiment.) Six experiments 

 of this character were made; the general form of behavior 

 manifested by the gloves in two of these experiments is 

 graphically shown in figure 22. 



In experiment 571 both gloves lost weight during the first 

 five hours of their suspension in the hypertonic solution, and 

 in the glove containing Ringer in which K was absent (571 1) 

 the loss was greater than in the glove in which K was present 

 (571J). While, in each instance, this loss resulted from 

 differences in osmotic pressure, the relatively slight loss in 

 weight of one of the gloves (571 J) indicates that the force 

 which drives water through the skin into the glove, in the op- 

 posite direction to that by which it is driven by osmosis, was 

 greater in one skin than in the other. This increase in the 

 rate of passage, due to the presence of K in the solution, 

 counteracted the full driving force of osmosis, so that the 

 glove containing Ringer in which K was present (571 J) lost 

 less water and consequently less weight than did the glove 

 containing Ringer in which K was absent (571 1) when the 

 gloves were suspended in the hypertonic saline solution. From 

 the fifth hour on, the glove containing Ringer in which K 

 was present (571 J) gradually made a gain which amounted 

 to about 92.5 per cent at the end of forty-six hours' suspen- 

 sion in the hypertonic solution. This gradual gain indicates 

 that after an equilibrium had been established between the 

 Ringer's solution in the glove and the NaCl solution in which 



