54 SCIENTIFIC FEEDING OF ANIMALS 



The loss of heat, or what is the same, the con- 

 sumption of tissue which takes place at o° can be 

 diminished by 50-60% when the surrounding 

 temperature is raised to 30 C. In this respect the 

 results of the experiment given above teach a great 

 deal. They show that the using up of tissue in a 

 fasting animal is in close and regular relation to 

 changes of the surrounding temperatures. Other 

 investigations confirm this and differences of i° C. 

 have in fact been clearly reflected in the loss of heat. 

 Animals cannot, however, stand higher tempera- 

 tures, such as 30-35 C, for the body becomes over- 

 heated and a condition of fever sets in. 



If a comparison is made between the behaviour 

 of the two dogs in the above experiment, it is seen 

 that the clipped dog (b) lost considerably more 

 heat at the lower temperatures, and that in its case 

 the raising of the temperature prevented more loss 

 of heat than with the long-coated dog (a). The 

 importance of a covering of hair on animals is 

 clearly shown in this way. 



In the production of heat in the fasting animal 

 it has been seen that both the body protein and the 

 body fat take part. The fatter the animal is the 



