RESPIRATORY EXCHANGE OF ANIMALS AND MAN 



heat regulation has been made by Rubner [1887, 1902], who found 

 for instance [1887] in a guinea-pig during a period of inanition the 

 following figures (Table XIV): 



TABLE XIV. 



At very high temperatures (above 35) the regulation breaks down 

 and the respiratory exchange rises with increasing temperature of the 

 body, as seen in the last experiment of the above series. A break- 

 down may occur also at low temperatures when the rectal temperature 

 falls considerably below the normal. This is well shown in a series of 

 experiments by Pfluger [1878] on a rabbit which was during the deter- 

 minations immersed in a water-bath. 



Rectal Temperature, 



per Kg. and Hour, 

 c.c. 



THE INFLUENCE OF TEMPERATURE UPON THE STANDARD META- 

 BOLISM OF ANIMALS. 



In all the experiments so far mentioned both on cold-blooded and 

 warm-blooded animals we have to do with two distinct effects of the 

 temperature, viz. one upon the central nervous system causing variations 

 in the innervation of different organs and especially of the muscles, 

 and one upon the tissues themselves influencing the reaction velocity of 

 the metabolic processes. In the warm-blooded animals the action 

 of low temperatures on the skin produces reflexly innervation of the 

 muscles resulting either in movements or in increase of tone. In 

 the cold-blooded animals the processes in the central nervous system 



