8i6 
Journal of Agricultural Research voi. xxm, no. io 
continued absorption of these metals the cumulative capacities of the 
plants seem to reach a limit, and then the organic metal aggregates in 
the cells begin to disintegrate. The rate of this action may be determined 
by the quantities of alkaline bases present in the plant sap. The fact 
also that the metals become “masked” or fixed in the plant tissues 
would probably explain their continued absorptions from the soil solu¬ 
tion, the rate of absorption being largely determined by their relative 
availabilities. 
QUANTITIES OF ALUMINUM PRESENT IN STALKS FROM DIFFERENT 
LOCALITIES 
The percentage of ash in cornstalks varies considerably for plants 
grown in different parts of the country. Analysis of a limited number 
of plants shows that their ash contents vary from approximately 3 to 
6.3 per cent. The aluminum content of the ash of the leaves also varies 
markedly, within a range extending from 1.75 per cent to as high as 5.06 
per cent in some plants. In fact, the aluminum content of the ash of dis¬ 
eased com plants obtained in 1920 from the Wanatah (Ind.) soil investi¬ 
gated by Abbott, Conner, and Smalley (1) was over 10 per cent. 
Table III contains a summary of the analyses of the ash and aluminum 
contents of normal and rootrotted plants selected in different localities. 
The aluminum content has been constantly greater in the diseased stalks 
than in the normally growing ones. These differences suggest a relation 
between the occurrence of the rootrots and the aluminum content of the 
stalks. 
Table III. —Percentage of ash and aluminum in normal and diseased stalks obtained 
from different localities in 1920 
Locality. 
Normal. 
Diseased. 
Number of 
stalks. 
Percentage 
of ash. 
Percentage 
of AI 2 O 3 . 
Number of 
stalks. 
Percentage 
of ash. 
Percentage 
of AlsOi. 
La Fayette, Ind. 
3 
3. 22 
I. 77 
11 
3-Si 
2. 80 
Sullivan, Ind. 
3 
2. 99 
2. OO 
8 
4.48 
3- 32 
Amherst, Mass. 0 . 
8 
6. 27 
4. 27 
Battleground, Ind. 
2 
4.71 
2. 21 
3 
4.27 
5.06 
o Diseased specimens only were received. 
Table IV. —Total ash content and percentage of aluminum in healthy and diseased stalks 
of Reid Yellow Dent from experimental plot at Battleground , Ind., in 1920 
Ash. 
AI2O3. 
8 healthy stalks. 
Per cent. 
3-64 
4.09 
1 
Per cent. 
I. 99 
3- 73 
21 diseased stalks. 
Table IV gives a direct comparison between specially selected stalks 
of Reid Yellow Dent variety. Various types of stalks showing symp¬ 
toms of rootrots were selected and checked against the normal-appearing 
stalks growing in the same soil with the same conditions for growth. 
