MANUAL 01^ CATTLE-FEEDmO, 131 



In eacli, the protein consumption was in equilibrium 

 with the food supply at the beginnmg of the experiment. 

 In the first case an iaereabe of 7U0 grms. in the amount of 

 meat eaten caused a rapid increase in the protein consump- 

 tion, till in three dajb the two were again nearly in equi- 

 hbrium. In the second experiment the same thing is 

 observed as to the decrease of the protein consumption. 

 The gain or loss of flesh in either case is very trifling, 

 amounting respectively to 335 grms. and 199 grms. in a dog 

 weighing about 35 kilogrammes. Xearly all of the addi- 

 tional Too grms. per day in the first experiment was con- 

 verted into circulatory protein and rapidly destroyed, while 

 in the second the subtraction of 500 grms. per day de- 

 creased proportionately the reserve of circulatory protein 

 and the amount consumed. 



The experiments given above are simply examples taken 

 from a large number of similar ones, made both on carnivora 

 and herbivora, all of which have given the same result, 

 viz. : the anhmil hodi/jnits itself ^ after a longer or shorter 

 tbne^ into equilihimih with wJmtever quantity of odbuTmn- 

 ^oids it receives in its fodder ahoi^e thai necessary to main- 

 tain it in average condition. That is, a certain minimum 

 quantity of albuminoids is necessary to prevent the starva- 

 tion of the animal. An increase of the supply above this 

 quantity causes a slight gain of flesh for a short time, but 

 a rapid increase in the amount of circulatory protein and 

 consequently in the protein consumption, and, finally, ex- 

 actly as much nitrogen is excreted in the urine (and milk) 

 as is taken in the food. We might compare the stock of 

 circulatory protein in the body to a mass of water con- 

 tained in a ve'^sel with a small aperture in the bottom, if 

 there is no supply, it quickly runs out. If a small stream 

 of water be let in at the top, a small supply of water may 



