THE UTILIZATION OF ENERGY. 479 
As was noted in the discussion of metabolizable energy in 
Chapter X, the results on Ox F appear to be exceptional, but those. 
upon the other two show considerable differences, and it is evident 
that further investigation will be necessary to obtain satisfactory 
data upon the effect of oil fed in this way. 
Kellner’s method of computation, based upon the provisional 
conclusion on p. 323, Chapter X, that oil has substantially no effect 
upon the loss of energy in urine and methane under normal condi-: 
tions, gives the following results: 
PERCENTAGE OF METABOLIZABLE ENERGY UTILIZED, 
As Computed As Computed 
by Kellner. on p. 462. 
OX Dieeiecss §2.2 51.6 
fe OH. fag aueac ke [tage heave ede: Sem Nh 65.1 
FS Giase re eee te 59.4 69.4 
DISTRIBUTION OF ENERGY OF DIGESTED OIL. 
Work of 
Digestion, , 
Ani- Period In Urine,| In Methane, | Assimilation | In Gain, 
mal. * }PerCent.| Per Cent. and Tissue | Per Cent. 
Building, 
Per Cent. 
Sample I........ D| 3 0 0 47.8 52.2 
: Vises eee ay G 5 0 0 40.6 59.4 
Average....... sucisGe a. [ee Seas 0 0 44.2 55.8 
Average computed 
as on p. 478....|..0..-]. e200 ee 0.5 —2.2 40.3 61.4 
The numerical results of these experiments show more clearly 
than was the case with the starch the difference in the two methods of 
computation. Both methods agree, however, in showing that the 
combined expenditure of energy in the digestion and assimilation of 
the oil and in tissue building is very considerable. We have already 
seen that the expenditure of energy in the digestion of fat by car- 
nivora and by man is comparatively small. If we are justified in 
assuming that the same thing is true of ruminants, the result just 
reached signifies that the digested fat undergoes extensive trans- 
formations before being finally deposited in the adipose tissue. 
