980 
Journal of Agricultural Research 
Vol. XXXI, No. 10 
The data for crude fiber in the stalk of corn are presented in Figure 
5. Mere inspection of the plotted observations is sufficient to show 
that they do not conform to the form of curve exhibited by the general 
equation as illustrated in Figure 1. Treatment of the data, however, 
as a two-cycle matter yields a theoretical curve that conforms beau¬ 
tifully to the observations. Just how well it may satisfy the reason 
is perhaps another matter. It involves the assumption that the 
second growth cycle is at its maximum velocity at the time of the last 
observation. Tnis assumption, it will be apparent, attaches great 
weight to the accuracy of the last observational value as representing 
the course of growth, and should be supported by other experimental 
work before full acceptance. 
Fig. 5 —Growth of crude fiber in stalk per acre of corn crop. Time (t) is reckoned in days from date of 
planting. Growth Or) is expressed as a percentage of 1,710 pounds. Equations to curves: 
109 loaf-? ” 0 - 075 tf- 66 - 5 ) 
l°g (t-m) 
Taken at face value, the data of Figure 5 indicate that the corn is 
potentially capable of a much greater growth in the reproductive 
stage than was actually realized, as far as the limitation of the tissues, 
represented by the present crude fiber data, is concerned. [There is a 
different relation for the crude-fiber data of the ear (fig. 9).] It is 
apparent from the data of Figures 4 and 5, that the crude-fiber 
growth curves of the sunflower and corn are distinctly different. In 
the first or vegetative cycle the sunflower has a low value of K (0.042) 
and the corn has a high value (0.075). In the second or reproductive 
cycle these relations are reversed—that is, the sunflower has a short 
f " and period” of growth (Z = 0.082) and the com has a long one 
= 0.033). 
As to the particular location of the growth in crude fiber in the 
stalk in the second cycle, the data of Figures 4 and 5 do not dis¬ 
tinguish. Presumably, the location is in part, at least, in those 
