516 PRINCIPLES OF ANIMAL NUTRITION. 
man, while in the dog it is apparently somewhat less, as is seen 
from the following comparison: 
Grade, Efficiency, 
Per Cent. Per Cent. 
Mat ssctacccucdat se 23 35.7 
OVS sic. eis eines eae 10.7 34.3 
OAS” creatine ® iNet eared 18.1 33.7 
DOS iisdinsaeinieess 17.2 30.7 
The energy expended in horizontal locomotion, on the other 
hand, showed more marked differences, viz.: 
Energy Expended 
Speed, Met 
| perMinute.” | ret, Ken 
DOG cms cashes dtabeas 78.57 0.501 
MAD soon ge hana ose 42 .32-74 .48 0.211-0.334 
OTE scncndaxaneias 78.00 0.138 
The relatively high figure for the dog is perhaps due in part to the 
considerable muscular effort apparently required (p. 499) to main- 
tain the erect posture. It has been shown by v. Hésslin,* however, 
by a mechanical analysis of the work of locomotion, that the latter 
does not increase as rapidly as the weight of the animal, but in 
proportion to its two-thirds power, or, in other words, approximately 
in proportion to the surface. If we compare the experiments upon 
_ different species of animals on this basis—that is, if we divide the 
total energy expended by the animal for locomotion by the product 
of the distance traversed into the two-thirds power of the weight 
—we obtain the following figures: 
DOB ey Sos hae trains aee eros ea ee 1.501 kgm. 
Mismatch no taki hs Seas 0.861-1.274 kem. 
Horse. spac Shen onde Baie lg 1.058 kem. 
Computed in this way, the figures for the horse and those for man at 
a comparable speed (74.48 M. per min.) do not differ greatly, and 
v. Hosslin’s conclusions are to this extent confirmed. The figures 
for the dog still remain higher than the others. If, in the case of 
* Archiv f. (Anatomie u.) Physiol., 1888, p. 340. 
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