PHYSIOLOGICAL CHANGES IN TRANSITION. 



267 



to 7 minutes, but here again the records were not continued a sufficient 

 length of time to determine whether the pulse-rate returned to the 

 normal value or remained at a higher rate for some hours, as was 

 observed by Benedict and Cathcart. 1 



Curve A in figure 31 shows a rise from an average rate of 64 to a rate 

 of 146 when the subject began to walk on a 30 per cent grade. When 

 he stopped walking at the end of the first period, there was an immediate 

 drop of 53 beats. When the walking began again, the pulse-rate rose 

 to 170, with a greater fall at the end of the second period of walking and 

 a still greater rise for the third period of walking. Curve B in figure 31 

 shows essentially the same characteristics as those of curve A in the 

 same figure. 



10 



FIG. 32. Typical pulse curves of E. D. B., with subject standing, and walking on an incline. 



(Values per minute.) 

 1, subject sitting; 2, standing; 3, walking on an incline. Black points, records during experimental 



periods; open circles, records between periods. Curve A, Feb. 15; B, Feb. 18; C, Feb. 17; 



D, Feb. 19; E, Feb. 22; F, Feb. 21, 1916. 



In figure 32 curves A and B represent pulse records obtained when 

 the walking was continuous and illustrate the gradual rise in the pulse- 

 rate due to the cumulative effect of the exercise. As no records 

 of the pulse-rate were made in the intervals between the walking periods 

 in the other experiments in figure 32, there is accordingly no picture 

 of the fall which took place while the subject was standing in these 

 intervals. (See C, D, E, and F.) The curves in other respects are 

 similar to those previously discussed, and show increases in the pulse- 



ict and Cathcart, Carnegie Inst. Wash. Pub. No. 187, 1913, p. 154. 



