PULSE-RATE. 437 



The pulse cycles of T. M. C. show a shortened duration for the first 

 six beats during walking, after which the duration lengthens until the 

 fourteenth cycle. The remaining portion of the curve exhibits no 

 rapid changes, though a gradual shortening of the duration takes 

 place after the twenty-sixth cycle, which is followed by another 

 gradual lengthening after the fifty-sixth cycle. At the transition from 

 walking to standing the pulse cycles had nearly the same duration as 

 at the end of the first transition period, but by the twelfth beat had 

 lengthened to 0.71 second and by the twenty-second beat to 0.83 

 second. A period of reaction then followed for the next eight beats. 



The curve of E. L. F. shows the rapid shortening of the cycle to 0.61 

 second at the eighth beat during walking, followed by four slightly 

 lengthened cycles, and a rise to 0.58 second for the twenty-fourth cycle. 

 From this point there is a rapid fall in the curve to 0.69 second for the 

 thirty-sixth cycle, which value it maintained with fair uniformity 

 during the remainder of this transition period. At the transition from 

 walking to standing, there appears the usual immediate lengthening 

 of the cycle followed by a period of eight beats, during which the cycle 

 again shortens. At the thirtieth beat, the cycle had reached its longest 

 duration of 0.73 second. From this point until the end of the record 

 the cycle continued to shorten so that at the close the duration was 

 0.62 second, which was shorter than the average during the walking 

 period. 



The curve of H. W. F. is unlike the other curves of this group or of 

 Squads A and B in that the pulse cycle undergoes no shortening in 

 the transition from standing to walking. It is true that during the 

 preliminary 15.2 seconds of standing, the duration had shortened from 

 the twentieth to the fourteenth cycles preceding the transition, which 

 was coincident with the warning that the walking was about to begin; 

 this effect had, however, passed away and a secondary shortening was 

 stopped and changed to a lengthened cycle when the walking began. 

 Although the records have been searched, no explanation for this 

 unusual behavior is apparent. In the case of H. M. S. no signal was 

 given and the starting of the treadmill was entirely unexpected by the 

 subject. The transition cycle therefore shows no influence of a pre- 

 liminary warning. The change in the duration of the pulse cycle during 

 walking was from 0.84 to 0.76 second in the first two cycles, and reached 

 0.71 second by the sixteenth cycle. The duration lengthened from 

 this point to 0.78 second at the twenty-sixth cycle. For the last half 

 of this transition record, the cycle lengths are unusually uniform, being 

 not far from 0.74 second. The curve for the transition from walking 

 to standing differs in no marked respect from the other curves except 

 that the thirteenth and fourteenth cycles indicate a sudden shortening 

 to an average of 0.66 second, with an immediate return to the previous 

 duration. 



