PULSE-RATE. 



423 



great uniformity, that is, the averages make very smooth curves. There 

 is apparently no significant difference with Squads A, B, and the 

 normal series of 1917 in the sharpness of the rise with beginning activity. 

 The absolute change in hundredths of a second between the level for 

 quiet and the level for activity is of course greater in those cases in 

 which the level for quiet is low, as for example, on January 27 with 

 Squad A (fig. 93), but, as we have seen previously, the percentage of 

 change is about the same in each case. The irregularity at the be- 

 ginning during the period of quiet is somewhat larger than would be 

 expected, judging from the curve for the series of 1917. These irregu- 

 larities, considered on the percentage basis, would not be as relatively 



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I 2 3 



Fig. 94. — Composite curves for changes in pulse-cycle duration with exertion, Squad B — 

 Records for 4 days with Squad B compared with the results for normal series of 1917. 



large as they appear in the figure. It seems probable that at the lower 

 pulse-rate the natural arrhythmia is accentuated. The descending 

 portion of the curves is usually consistent in its uniformity until it 

 reaches approximately the sixteenth pulse-cycle. Subsequently there 

 is considerable fluctuation. From figure 93 it would appear that the 

 return in the direction of the basal level for quiet is more prompt 

 for Squad A than in the case of the normal series for 1917. If one had 

 only these data it might be taken as an indication of a different condi- 

 tion due to the lower pulse-rate during the reduced diet. When we 

 compare the curves for Squad B, however (see fig. 94), we find no 

 sensible difference in their slope as compared with the normal series 

 of 1917, and the normal curves of Squad B compare very favorably 

 with those taken during the period of reduced diet. 



