PULSE-RATE. 



421 



parison, summarized in table 96. In this are embodied, also, the 

 results of normal series of 1917. Records, usually two for each man, 

 obtained with 63 normal aviation candidates enter into this 1917 

 series. The technique employed with these men was identical with 

 that used in this investigation and described on page 151, except 

 that the first trial was not a practice trial without a record, as in the 

 low-diet investigation, but with the aviators a record was taken. Thus 

 the pulse-rate in the first record for the aviators was affected somewhat 

 by the factor of excitation and novelty. It is possible that this in large 

 part accounts for the difference between their average of 83 for the 

 quiet pulse-cycle length and 92 for the normal average of the same 

 measurement with Squad B, and likewise for the fact that the activity 

 and rest values, 60 and 65, are shorter than the normal values of Squad 

 B, I. e., 67 and 70. However, both the normal values for Squad B and 



those in the series of 1917 definitely show shorter pulse-cycle lengths 

 than the values for the low-diet period of Squad B and those of Squad A. 

 Compared on the basis of percentage of change of the activity over the 

 pulee-cycle length during quiet, we have for Squad A 29 per cent and 

 for all the others 27 per cent — surely a remarkably close correspon- 

 dence. The percentage of change in the 20 pulse-cycles following 

 activity, as compared to the quiet pulse-cycle length, is for Squad A 22 

 per cent, while that for the normal series of 1917 is 21 per cent. With 

 Squad B, also, the low-diet value is 1 per cent larger than the normal, 

 being 26 per cent as compared with 25 per cent. As was mentioned 

 earlier, certain of the members of Squad B demonstrated individual 

 peculiarities, having a faster pulse than would normally be expected 

 after activity. 



Finally, we may compare the composite curves, which show not 

 simply the levels in the three different conditions, quiet, activity, and 

 rest, as presented and discussed in tables 94, 95, and 96, but also demon- 

 strate the transitions and the progressive changes between these. An 

 average was made for the comparable pulse-cycles of the 10 subjects 

 of Squad A for three of the dates on which such tracings were taken 

 for these men.^ The average values obtained for these dates, to- 



* We have omitted from the average the records of Kon and Spe. 



