1] 



UPON THE RATE OF GROWTH 



453 



21 



.13 11 15 16 17" 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 31 35 30 37 3839 40il 



FIG. 129 



MM. 



70 



\ 



15 17 19 21 



25 27 29 31 

 FIG. 130 



37 39 





