1] 



UPON THE RATE OF GROWTH 



453 



280 

 260 



210 



13' li' 15 16 17 18 19 "JilT 21 2a 23 21 25 26 27 28 29 30 31 32 33 31 35 36 3', " 3S 3 10 il" 



FIG. 129 



MM. 



15 17 19 21 23 25 27 29 31 33 35 37 39 



