PHYSIOLOGICAL CHANGES IN TRANSITION. 279 



81 and 82 were obtained by measuring these kymograph records. The 

 length of time the subject had been standing previous to these transi- 

 tion observations varied considerably, the range being 10 to 50 minutes. 

 As the condition in the transitional periods varied widely, averaging 

 the values, as was done in the regular series of experiments, would give 

 results without significance. The results of each period have therefore 

 been grouped separately and the measurements of the respiration, 

 ventilation, and oxygen consumption for fractions of a minute have 

 been tabulated on the per minute basis. The data for pulmonary 

 ventilation and oxygen consumption, as given in tables 81 and 82, have 

 not been corrected for the temperature changes, as they are intended 

 for approximate comparison only. 



CHANGES IN RESPIRATION-RATE. 



The data for the respiration-rate are given in table 81. The respira- 

 tions during the standing before walking were measured from the 

 kymograph curve for full minutes, no measurements being made of the 

 respiration during the last minute of standing, when the blanket was 

 removed from the subject before he began walking. During the first 

 minute of walking each measurement covered approximately 12 seconds 

 and in the succeeding minutes 15 seconds. As given in the table, 

 however, the respirations for these fractions of a minute have been 

 computed to a per minute rate. 



By inspecting the figures in table 81, it will be seen that the respira- 

 tion-rate for standing was fairly uniform during the time of measure- 

 ment, the changes from period to period being slight and thus in keep- 

 ing with the measurements in the standing experiments previously 

 discussed. (See p. 101.) This gives evidence that the respiration-rate 

 had returned to its normal standing value following the walking of the 

 preceding period. In the majority of the periods the increase in the 

 respiration-rate for the first one-fifth minute of walking was at the rate 

 of from 8 to 10 respirations per minute, or, in round numbers, an in- 

 crease of 50 per cent over the standing rate. During the following frac- 

 tion of the first minute there was, on the whole, a tendency to a further 

 increase at the rate of 1 to 3 respirations per minute, though in a few 

 instances there was a fall. The major portion of the increase occurred 

 within the first 12 seconds. In the following minutes, measured in 

 15-second intervals, the rates were, as a rule, higher as the time ad- 

 vanced, and though there are periods when constancy was apparently 

 reached by the second minute (see second period of March 9, fourth 

 period of March 15, and second, third, and fourth periods of March 17), 

 there are others (March 16 and February 24) which show gains through- 

 out the record. The change in the rate due to transition from standing 

 to walking, except with severe grades (see March 16 and February 24), 

 may be said to occur, however, in the first minute, and the most of 

 the change is in the first 12 seconds. 



