THE RELATIONS OF METABOLISM TO FOOD-SUPPLY. 171 
Fat of | Fat from Fat of 
. Total, rs 
Fodder, | Protein, Grme. the Milk, 
Grms. Grms. Grms. 
Voit: | Experiment Ged ngreaciia aa 318.8 | 401.8 | 720.6 | 577.5 
Devaar paige Gass 276.0 | 308.5] 584.5 | 337.3 
Hua & Pinter: | Bivens] ies.g | 8-8] 8.0 | arr 
Fleischer: {SPERMS Tycc cs] 188'8 | 70:0 | 3368 | 30:8 
regard the differences as within the limits of error in such experi- 
ments. 
Studies of the results of fattening experiments with ruminants 
give similar results. On the basis of Lawes & Gilbert’s determi- 
nations of the composition of the increase of live weight in fattening, | 
the amount of fat produced in such an experiment may be approxi- 
mately computed and compared with the amounts of proteids and 
fat in the food. Such a comparison by the writer * in seventy-seven 
experiments on sheep showed that, with one or two possible excep- 
tions, the fat and proteids of the food were sufficient to account for 
the amount of fat formed, although in some of the experiments 
little margin was left. 
Experiments on Swine-—Experiments with swine, on the other 
hand, as Wolff t has shown, have almost without exception given 
results which can scarcely be explained except upon the hypothesis 
of a formation of fat from carbohydrates. These animals, as Lawes 
& Gilbert pointed out in their early papers, are especially adapted 
to experiments of this sort, since they consume a relatively large 
amount of easily digestible food, have a small proportion of offal to 
carcass, and are by nature inclined to lay on fat readily. It was 
therefore to be expected that experiments upon swine would ‘show 
a production of fat from carbohydrates, if such took place, more 
decisively than those upon ruminants. 
Experiments on pigs by Weiske & Wildt,{ it is true, on the 
same plan as those by Lawes & Gilbert, yielded results consistent 
with Voit’s theory, showing a formation of 5565 grams of fat in the 
* Manual of Cattle Feeding, p. 177. 
+ Erndhrung Landw. Nutzth., pp. 354-356 
t Zeitschrift f. Biol., 10, 1. 
