66 



GROWTH IN. TOTAL BODY WEIGHT 



data (Donaldson, MS '14). After the 14th day the weighing 

 of 19 males and 17 females was made at frequent intervals, so 

 long as the animals kept in good condition. Tables 63 and 64 

 give for males and females respectively not only the mean values 

 but the range, and in the case of the females, after 90 days, the 



Chart 2 Growth in body weight on age. Male albino rat. 



A. Observations of Donaldson, Dunn and Watson ('06) . See table 63. 



B. Observations of Ferry, '13. See table 65. 



B'. Observations of Ferry, '13. See column 2, table 65. 



C. Observations of King (MS '15). Data from two series combined. See 

 table 67. 



observed values for the unmated animals are accompanied by 

 a second series of values computed for mated rats on the basis of 

 Watson's ('05) observations which show that mated females gain 

 in weight about 0.03 per cent per diem faster than the unmated. 

 These data are used for graph A, chart 2, males, and graph A, 

 chart 3, females. 



