216 PRINCIPLES OF ANIMAL NUTRITION. 
all cases the animal was liberally fed, usually with oats, hay, and 
cut straw. 
VARIATION DURING Worxk.—lIn their experiments cited above, 
Chauveau & Laulanié find that the rise of the respiratory quotient 
which they regard as the invariable result of muscular exertion 
occurs promptly upon the beginning of the work, and the same thing 
is shown by the earlier results of Chauveau. As the work is con- 
tinued, however, the quotient shows a tendency to fall again, some- 
time even going below its original rest value, while in a period of 
rest following work a still further decrease is observed. The 
results of their experiments * are contained in the table on the 
- opposite page. 
Zuntz & Hagemann f also report a number of experiments on 
the horse in which the respiratory exchange was determined in suc- 
cessive periods of work. The following are their results for the 
respiratory quotient: 
ae Successive Values of Respiratory Quotient. Aggregate Length 
Experiment. of Wark Fenads, 
1 2 3 : 
917 .865 rer 80 
913 .806 re 1214 
929 .889 er 102 
925 .948 .897 100 
920 .931 .875 924 
865 .868 911 54 
928 .921 34 
.910 .926 Te 48 
.974 - 905 -837 65 
.863 .820 eeeiehe 73 
911 -922 ere 71 
.949 .934 .871 124 
.936 -909 .878 78 
-931 - 904 .883 75 
The results cited in the foregoing paragraphs would appear to 
justify the general conclusion that in the case of fasting animals or 
* Comptes rend., 122, 1244, 
t Loc. cit., pp. 290-292, 
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