PULSE-RATE. 



83 



TABLE 20. Comparison of average minimum pulse-rates of boys and giils. 



we exclude the first 5 days, and from 105 to 125 if these earlier values 

 are included. Thereafter the picture is a gradual decrease, persisting 

 throughout the second and much of the third year. The data between 

 3 and 6 years are lacking. During this period there has been a very 

 considerable fall, the tendency to a decrease continuing subsequent 

 to 7 years. The lowest value is 69 at the age of 12 years. With girls, 

 the averages show that after the first 11 days there is a distinct ten- 

 dency for a rise in pulse-rate, the return to the rate of the first week 

 not taking place until shortly after the end of the first year. There is 

 then a continued decrease, the lowest record being 74 at the age of 

 7 years. 



SEX AND MINIMUM PULSE-RATE. 



The intimate relation between pulse-rate and metabolism, shown 

 with the same individual in the large majority of observations in this 

 laboratory, makes a careful examination of pulse-rate with respect to 

 sex of special importance. The analysis of data for the basal metab- 

 olism of men and women has shown that women as a class have a 

 lower metabolism than men, not only per individual, but per unit of 

 weight. On the other hand, the pulse-rate of women as a class was 

 shown to be higher than that of men, as measurements for 90 women 

 and 121 men in our series gave an average of 68.67 for women and 



