HYDE: EXPERIMENTS ON THE SKATE. 



43 



The results of the experiments with CaCk are briefly tabu- 

 lated in table III and partly shown in curves. It was observed 

 that after an injection of the usual amount of m/32 CaCk 

 solution (curves 15, 16), the blood pressure remained un- 

 changed. Respiratory activity was usually increased for one 

 to three minutes, and the cardiac contractions continued un- 

 changed or did so after about one minute of decreased rate and 

 increased force. Following an injection of an m/8 CaCk solu- 

 tion, the rate of cardiac and respiratory activity is usually de- 

 creased and the force of both increased. The blood pressure 

 rises for about one minute. Often systole and inspiratory 

 phases predominate, and furthermore, the solution proved an- 

 titoxic to many toxic salt solutions. The effect of an m% CaCk 

 was first a decrease in rate of cardiac and respiratory activity, 

 often irregular, with prolonged systole and inspiratory phases. 

 The force of both activities was usually increased, as was also 

 the blood pressure, for from one to three minutes. If the force 

 of the heart-beat was not increased the blood pressure did not 

 rise above normal. 



Table III. Mean results in respiration, heart action and blood pressure, 

 following injections of different concentrations of CaCls solutions. 



Curve 15. Following an injection of m/32 CaCl2. 



' Curve 15 



2-Univ. Sci. Bull.. Vol. V, No. 4. 



