PEVER 703 



mask the fever. The positive result of the puncture in curarized 

 animals, which some observers say they have obtained, would, if 

 animals, which some observers say they have obtained, would, if 

 confirmed, be important evidence that the primary effect is not on 

 the muscles, or, at least, not solely on them, but would not prove 

 that it is on the liver. That the liver is concerned, however, is more 

 directly indicated by the fact that during the puncture fever the 

 liver continues to be what it is under normal conditions, the warmest 

 organ in the body, warmer than the blood in the root of the aorta 

 by about i C. The most probable conclusion is that the increased 

 production of heat in this form of experimental fever is due to an 

 increased metabolism of carbo-hydrate (glycogen) both in the liver 

 and in the muscles. 



Temperature Regulation in Hibernating Animals. The behaviour 

 of hibernating mammals, such as the marmot, dormouse, hedgehog, 

 and bat, is of interest in connection with the temperature regulation. 

 In the active waking state these animals are homoiothermal, but in 

 profound winter sleep they are poikilothermal, the body-tempera- 

 ture rising and falling with that of the air. The rectal temperature 

 may be as low as 2 C. There is an intermediate state in which the 

 animal is partially awake, though inactive, and its temperature is 

 much below the normal, but considerably above that of its environ- 

 ment. In this condition it has an imperfect thermotaxis, something 

 like that of an ordinary mammal (including the human infant) in 

 the period of immaturity, immediately after birth. When the 

 hibernating mammal awakes the rise of temperature is enormous 

 and abrupt. The temperature of a dormouse rose in an hour from 

 13' 5 C. to 357 C., and that of a bat in fifteen minutes from 17 C. 

 to 34 C. (Pembrey). 



Fevers. Fever is a pathological process generally caused by the 

 poisonous products of bacteria, and characterized by a rise of 

 temperature above the limit of the daily variation (p. 712). It is 

 further associated with an increase in the rate of the heart and the 

 respiratory movements, and a diminution in the alkalies and carbon 

 dioxide of the blood. The total excretion of nitrogen is increased, 

 at least in proportion to the amount of protein ingested, indicating 

 an increase in the consumption of tissue-protein. The distribution 

 of the nitrogen among the urinary constituents is altered. The 

 ammonia (in the form of ammonium salts of organic acids), the 

 uric acid, and to a smaller extent the creatinin (Leathes), are in- 

 creased, while the urea is relatively decreased, even when its abso- 

 lute amount is greater than normal. Creatin, which is not normally 

 present in urine, unless the food contains it, may also appear in 

 fever (Shaffer). It has been suggested that the proximate cause of 

 fever is the action of bacterial poisons or of other substances on the 

 ' heat centres,' and that antipyretics, or drugs which reduce the 

 temperature in fever, do so by restoring the centres to their normal 



