SOME SPECIAL REGULATIVE PROCESSES $21 



man would be instantly killed, because evaporation of the 

 sweat would be prevented" (Leonard Hill, M. D.). If 

 the cells of either plant or animal life be subjected to a 

 temperature of 114 or over, the life of the protoplasm is 

 destroyed beyond recovery. 



581. Breathing and the Temperature. Since oxygen is 

 the supporter of combustion and carbon dioxid retards 

 combustion, the quantity of oxygen and carbon dioxid in 

 the body affects the temperature. When the body is at 

 an abnormally high temperature, as during a fever, the 

 breathing is generally more vigorous than usual. Those 

 animals, such as the bat, that hibernate and go without food 

 in cold weather, cease breathing altogether during the 

 trancelike condition, and their temperature sinks nearly to 

 freezing point. The absence of the oxygen, other than 

 what may diffuse through the windpipe into the motionless 

 lungs or through the skin, and the accumulation of carbon 

 dioxid, cause the fire of life to sink very low. 



582. The Source of Animal Heat is the combustion of the 

 food in the body by the oxygen. Wherever cell activity 

 is taking place, heat is produced. The muscles are the 

 greatest heat producers of all the organs. Their activity 

 gives rise to one half the heat of the body. A frog's body 

 keeps at the temperature of the surrounding objects in 

 winter and summer. He cannot stand the heat of summer 

 and retires to a cool ditch or well. In winter he buries 

 himself to escape the cold. He is stimulated by warmth 

 and benumbed by cold. Man and other warm-blooded 

 animals, on the contrary, are stimulated by cold and are 

 less active during warm weather. The temperature of 

 birds is 104. A chick before hatching is like a cold- 

 blooded animal. As soon as it begins to peck its way out 

 of the shell, it begins to acquire the power of regulating 

 its temperature ; the power may be acquired in a few 

 minutes. This new power comes from the new muscular 



Y 



