THE UTILIZATION OF ENERGY. 517 
this animal, we compare the total metabolism in locomotion with 
that during standing instead of lying, as was done in the case of 
the horse, the figure is reduced to 1.303 kgm., or not much higher 
than in the case of man. It must be remembered, however, that 
the figures above given for man include the metabolism due to 
standing. 
InprvipvaLity.—Zuntz & Hagemann’s investigations show that 
the efficiency of the horse is affected to a considerable degree by 
the individual differences in animals. The experiments whose 
results are summarized on p. 510 were upon a single animal 
(No. III). In addition to these a small number of experiments 
were made with several other animals, mostly old and more or less 
worthless ones, besides the considerable number upon Horse No. II 
previously reported by Lehmann & Zuntz.* The results are com- 
puted by the authors in terms of energy and corrected for speed 
upon the basis of the results obtained with Horse No. III. 
In a single case the work of ascent required slightly less expen- 
diture of energy than with Horse No. III, and in another case the 
work of horizontal locomotion, computed to the same live weight 
in proportion to the two-thirds power of the latter (see the oppo- 
site page) was also less than for Horse No. III, but as a rule these 
old, defective horses gave higher results. For ascent, omitting 
one exceptional case, the range was as follows: 
Per Kgm. of Work. 
Minimum....... 5.906 cals. = 39.84 per cent. efficiency 
Maximum....... 9.027 “ =26.07 “ “ ee 
Horse No. III... 6.851 “ =34.30 “ “ 
With one very lame horse (string-halt) the figures reached the 
maximum of 12.343 cals., or an efficiency of only 16.6 per cent. 
A similar range was observed in the results on horizontal loco- 
motion. Reduced to a speed of 78 M. per minute and to the live 
weight of No. III, the range was as follows: 
Per Meter and Kilogram Live Weight. 
Minimum..........02 cece cece eee eeees 284 eal. 
Maximum... ... cece cece cece e ee eee eenes 0.441 “ 
‘Horse Now lL i iiesece a eae serena sees 0.336 “ 
* Landw. Jahrb., 18, 1. 
