1] 



UPON THE RATE OF GROWTH 



453 



IS !!" 15 16 U : ie 19 M* 21 22 23 24 25 2627 28 28 30 31 32 33 31 35 3C J, 3s3S> i0 ll' 



FIG. 129 



15 17 19 21 03 25 27 39 31 33 35 37 39 



