58 THE ROYAL SOCIETY OF CANADA 



figures for carbon dioxide are much too low. It was found that one 

 litre of tap-water contained 9-3 c.c. of carbon dioxide, 5-3 c.c. of 

 oxygen, and 25-4 c.c. of nitrogen. This result shows a value for 

 oxygen much below that for saturation, agreeing with known results 

 for other underground waters.^ 



According to Bohr^ whose conclusions are based chiefly on A. 

 Krogh's experiments, the skin of the frog permits simple diffusion, 

 with no regulatory mechanism. The lungs provide the regulatory 

 mechanism. The skin allows a fairly constant diffusion, and takes 

 part especially in the excretion of carbon dioxide. The oxygen- 

 intake through the skin is almost constant, and independent of the 

 total magnitude of the metabolism. The greatest variations are only 

 from 43 to 60 c.c. per kilogram per hour. The carbon dioxide ex- 

 cretion through the skin is on the whole greater, and varies more 

 (from 92 to 179 c.c. per kilogram per hour). The corresponding 

 figures for the lung respiration are, for oxygen-intake, 51 to 390 c.c, 

 and for carbon-dioxide output, to 90 c.c. 



Pembrey,^ in Schafer's Textbook, states "Edwards found 



that frogs deprived of their lungs would live a long time, provided 

 that the external temperature was low. This cutaneous respiration 

 took place as readily in flowing water as in air, provided that the 

 temperature of the water did not exceed 12°." He further states 

 that Valentin found that absorption of oxygen was more active than 

 discharge of carbon dioxide through pieces of skin removed from the 

 body, while, on the other hand, Waymouth Reid and Hambly found 

 no evidence of any secretory action, exchange of gases, according to 

 these investigators, being the direct result of a difference of tension 

 on the two sides of the respiratory septum. 



Bearing these results in mind, the data yielded by our experi- 

 ments lead to the following conclusions. 



Frogs immersed in Winnipeg tap-water live normally, respiration 

 proceeding through the skin, the oxygen necessary being furnished 

 by the gases dissolved in the water. After a certain time, varying 

 over a wide range with the individual, absorption of water takes place 

 accompanied in most cases by absorption of gas. The water is ap- 

 parently absorbed by all muscular tissue, there being marked oedema, 

 and further, in the form of a diluted lymph distends all the lymph 

 spaces, giving the animal a marked dropsical appearance. The gas, 

 which consists of nitrogen (and probably of course argon) with one 



1 See F. W. Clarke, "The Data of Geochemistry," Bull. No. 330, U.S. Geological 

 Survey, 1908, p. 402. 



2 Bohr, Nagel's Handbuch de Physiologie, 1909, Bd. I, S. 160. 

 ^ Pembrey, Schafer's Textbook of Physiology, vol. I, p. 723, 1898. 



