52 THE ROYAL SOCIETY OF CANADA 



we have not found in the literature at our disposal any reference to 

 the phenomenon of gas-absorption and retention, though liquid 

 absorption under suitable conditions has been frequently studied, 

 we shall first give an account of our own experiments, and then quote 

 such previously ascertained facts as bear upon them. 



Late winter and spring specimens of R. pipiens, obtained from 

 Illinois, were used throughout the following experiments. 



A series of preliminary experiments were first performed. They 

 indicated that frogs survived in boiled out water (in stoppered vessels) 

 for periods of a few hours only, such times corresponding to those 

 which they can survive in an oxygen-free atmosphere. Some frogs 

 placed in a vessel through which flowed a constant stream of Win- 

 nipeg tap-water, in which they remained completely immersed, 

 died in three or four days, becoming swollen and buoyant before 

 death. The tissues, (heart, muscle, peripheral nerve, brain and cord) 

 were not killed when somatic death had taken place, but responded 

 to electrical stimulation. 



A series of four experiments were carried out in a similar way to 

 that just described. The first, second, and fourth can be used to 

 compute the average time of survival of frogs immersed in Winnipeg 

 tap-water. Living frogs in the third experiment were used to furnish 

 various data required during the course of the investigation, so that 

 this experiment cannot be used in determining the average. The 

 frogs were observed once or twice daily, so that the figures for the 

 time of death apply to some period during the preceding 24 hours, 

 and the whole number of the average should perhaps be one integer 

 less. The temperature of the tap-water during these experiments 

 varied from 5° to 12°C. The daily variation was of a similar order. 



Experiment 1. Commenced on February 1st, 1915. Four 

 frogs were immersed in a wide-mouthed jar, containing about 5 litres 

 of water. A wooden framework kept them below the surface of the 

 water. A fairly fast stream of water was allowed to run through 

 the containing vessel. Two frogs died during the fourth day of im- 

 mersion, one during the seventh, and' one during the seventeenth. 

 The frog which survived for the longest period was a male. The 

 sex of the others was not observed. All were swollen and buoyant. 

 The swelling and buoyancy became marked a day or two before death. 



Experiment 2. Commenced on February 18th, 1915. Eight 

 frogs, four male and four female, were immersed in the same vessel. 

 The females died, two in six days, one in eight days, and one in ten 

 days; the males died, one in six days one in eleven days, one in twenty- 

 four days, and one in forty-eight days. All were swollen and buoyant 



