THE UTILIZATION OF ENERGY. 543 
the food are too low. Either 3300 grams of fiber-free nutrients 
(18,068 Cals.) is too large an allowance for maintenance, or the 
assumption that the energy of the digested crude fiber is substan- 
tially equivalent to the work of digestion and assimilation is erro- 
neous, or, finally, the figure of 3.96 Cals. per gram of digested nutri- 
ents is too small. As regards the latter possibility, while it may 
be conceded that the energy per gram of digested matter will vary 
somewhat in different experiments, the difference will be too small 
to materially affect the result. The uncertainty regarding the 
maintenance requirement may be readily eliminated by a computa- 
tion based on the differences between the several periods, thus afford- 
ing, to a degree at least, a test of the correctness of Wolff’s hypothe- 
sis regarding the’ crude fiber. The following table contains the 
results of such comparisons. In each series the period with the 
least amount of digested food (fiber-free) has been compared with 
the other periods of the same series. 
Matehaliveble 
nergy 0: 1 
‘bem Work, Utilization, 
Nutrients. Cals. Bor Cont, 
Cals. 
1891-92. 
Period III............... 20,949 2663 
TW oosens eince ene eine 18,707 2197 
2,242 466 20.79 
Period IV...........---- 22,013 2581 
OO ANG shin ececeneioha see 18,707 2197 
3,306 384 11.62 
1892. 
Period Ja-d...........--- 20,094 2535 
SGD D ng iss io Siete cea 19,091 2152 
1,003 383 38.19 
Period IIb.........00505> 20,484 2720 
BO OSL on iesrale ase eeayae 8 19,091 2152 
1,393 568 40.77 
Period IV...........---: 20,433 2799 
OOo Te ees aade wnata siseietas 19,091 2152 
1,342 647 48 21 
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