THE RATE OF GROWTH 



101 



slower decline as we find in the guinea-pig. The 

 curve again is very irregular because I had only a 

 very limited number of observations upon the weight 

 of chicks. 1 The other sex, as the next slide will 

 show, presents similar phenomena, though the female 

 chickens do not grow quite as fast as their brothers. 

 Here we notice an initial increase of almost, but not 

 quite, nine per cent., which rapidly diminishes. After 



FIG. 33. CURVE SHOWING THE DAILY PERCENTAGE INCREMENTS IN WEIGHT 

 BY MALE CHICKENS. 



the chick is two months old it never adds as much as 

 $% per diem to its weight. It loses in the first two 

 months from a capacity to add nine per cent., down to 

 a capacity of adding less than three daily. It loses 

 in two months two thirds of its power of growth, 

 for from nine to zero is divisible into two parts, of 



1 See Appendix No. II, 



