PULSE-RATE. 427 



cycle continued until the tenth cycle after walking started, which was 

 0.80 second; it then remained practically constant through the six- 

 teenth beat, after which the duration began to lengthen again and 

 continued lengthening until the twenty-second cycle. There followed, 

 then, a period of some shght variations up to the thirtieth beat, after 

 which a second period of quickened pulse — i. e., shorter duration of 

 pulse cycle — set in and by the time of the thirty-fourth cycle it had 

 returned to the value observed at the tenth cycle. This corresponds 

 approximately to 29 seconds after the walking started. From this 

 point therp was a gradual lengthening of the pulse cycle to the close of 

 the record. The last cycle of the transition period corresponds to a 

 duration of 0.83 second, which was after 59.7 seconds of walking. The 

 pulse-rates taken for the sixth, twelfth, and twenty-fourth minutes of 

 the succeeding interval of walking appear here as a short curve and 

 show, in a general way, the relation of the pulse to the transitional 

 rate as the period progressed. It is seen in the final portion of the figure 

 that the duration of the pulse cycle was nearly uniform for the 10 

 cycles preceding the close of walking, and was 0.77 second at the 

 moment of transition. The average of the first two pulse cycles of the 

 standing period shows an immediate lengthening to 0.82 second, when 

 again a period of shortening rate followed, which was maintained, 

 more or less irregularly, for 34 beats during the next 27 seconds. 



The curve for Har (figure 95) is fragmentary, as certain portions of 

 the time record of the photographic film were illegible and the first 

 direct reading of the walking pulse comes approximately 4.5 seconds 

 after the transition. This shows a change in the duration of the pulse 

 cycle from 1.24 second at X to 0.84 second as the average of the fifth 

 and sixth cycles. Between the tenth and twentieth cycles the records 

 are missing, but the twentieth shows a slight lengthening, after which 

 a shortening of the pulse cycle took place which reached its maximum 

 at the forty-fourth cycle and was maintained with slight variations to 

 the close of this part of the record. During the rest of the walking 

 period, the pulse cycle lengthened somewhat, and by the time of the 

 final transition was 0.84 second. When the subject stopped walking 

 the cycles immediately began to lengthen and were 0.99 second at the 

 end of the record. 



Other members of the squad present similar pictures in the curves 

 given in figures 96 and 97. In the case of Kim (figure 96) the duration 

 was 0.79 second with the third and fourth cycles after walking began; 

 a marked lengthening to 0.93 second appeared in the average of the 

 fifth and sixth cycles. This was followed by a series of periods of 

 changing length of the pulse cycles which appear to indicate a rhythm 

 in the pulse. In the transition from walking to standing the first 

 immediate lengthening was followed by a shortening of the cycles, 

 so that the cycle is shorter from the tenth to the fourteenth cycles 

 after walking ceased than during the walking period. 



