ANIMAL TEMPERATUKE. 125 



disintegration of the muscular fibre in particular affects the 

 animal temperature. The temperature of the ox, like that of 

 mammals in general, is about 100 of Fahrenheit's thermo- 

 meter. As generally at the earth's surface, and particularly in 

 such a climate as that of the British Islands, the temperature 

 of the atmosphere is much below that just indicated, it is ob- 

 vious that the body of the ox must be continually losing heat, 

 and that unless it contained within itself a constant source 

 thereof, its heat would soon descend to the present temperature 

 of the air. 



It is quite correct to say that the temperature of the body 

 is entirely maintained at the cost of the blood. The greater 

 the degree of external cold, the greater is the waste of blood 

 required to maintain the uniform temperature. If an animal 

 be kept at rest in cold air, it will cool down much faster than 

 if it be exercised. But the additional heat produced by exer- 

 cise is at the cost of the loss of weight by the bodily frame, 

 and in the first instance by the blood. 



A great deal has been written of late as to the effect of such 

 aliments as starch, sugar, and oil in the maintenance of animal 

 temperature. And, doubtless, the facts stated are in a general 

 way quite correct. But it should not be forgotten that mus- 

 cular exertion, even in an animal at rest, never entirely ceases, 

 and therefore that there is always some amount of disintegra- 

 tion of the muscular fibre going on ; and therefore that when 

 the air is not cold, while moderate exertion is maintained, 

 the amount of disintegration so produced may be suffi- 

 cient to keep up the animal temperature. Thus it is certain 

 that, under all circumstances, animal temperature is main- 

 tained at some cost of blood expended in the repair of the 

 organic tissues disintegrated even in a state of rest. Nor 

 does the blood fail to suffer loss even in the preparation of 

 such substances as starch, sugar, and oil, before they become 



