THE RELATIONS OF METABOLISM TO FOOD-SUPPLY. 171 
Fat of Fat from 
Hodder, | ‘roi, | Eoin | the, 
Voit: | Experiment ee ee ee 318.8 | 401.8 | 720.6 | 577.5 
she & Fleischer: | Experiment 1”) 188.3 | °79:8| 303.0 | 277.3 
Fee | Hepecinent 1. Saues a 170.8 158.8 309 0 303.8 
: “ bt eer ee 166.5 170.0 336.5 290.5 
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 + 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. 
+ Ernihrung Landw. Nutzth., pp. 354-356 
t Zeitschrift f. Biol., 10, 1. 
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