176 



GROWTH IN TOTAL BODY WEIGHT 



weights have been computed for each day of age from 10 days 

 on — see table 157. 



The values given for the first ten days of age in table 157 

 have been obtained from a revised series of direct observations 

 Donaldson ('15). 



The weight at birth as here given, is for rats that have suckled. 



Using a group of 148 males and 158 females, composed of 

 animals which were specially well cared for and fed, Greeman 



10 20 30 Id 50 M 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 2-W 250 260 270 280 250 300 310 320 330 3« 350 :&: 370 



Chart 22 Growth of body weight on age. Female albino rat. A. Observa- 

 tions of Donaldson, Dunn and Watson ('06). See table 157. B. Observations 

 of King ('15). Data from two series combined. See table 121. 



and Duhring ('23, page 4, chart no. 1) have recorded a growth curve 

 for the males which after a hundred days shows higher values 

 than those just given. At 350 days this special group surpasses 

 our male values by 65 grams and the curve is still rising. 



In the case of the females the superior treatment and food pro- 

 duce animals which are about 15 grams heavier at 100 days and 

 about 18 grams heavier at 350 days. As so often happens the 

 greater response is given by the males — table 157 a. 



