41 
Amount of peroxidase present in chlorotic plants grown on soils containing different 
percentages of calcium carbonate. 


outan Compara- 
aCOz in tive 
malt Appearance of leaves. TOE 
peroxidase. 
Per cent. 
Wone. | Green... 2. 2 10 
5 | Slightly chlorotic...... Tae 
aoe ne Se See 10 
a3. jsChiorotic: £. 24...%s =. - 8.3 
- ie Ose ees se. 5 



The leaves of the plants grown in pot experiments I, II, and IV 
(see pp. 23-25) were also tested for peroxidases. In these cases leaves 
were taken from two check plants, one from the largest and one from 
the smallest of the five grown. The results are given in the table 
below, the arrangement of which is the same as the preceding table. 
Amount of peroxidase present in chlorotic plants grown on soils containing different 
percentages of calcium carbonate. 


Plants from Experiment I. Plants from Experiment IT. Plants from Experiment IV. 
Compar- Compar- Compar- 
ative ative ative 
CaCO3 em peareaee amount | CaCO; | Appearance | amount | CaCO; | Appearance | amount 
in soil. of leaves. of in soil. of leaves. of in soil. of leaves. of 
peroxi- peroxi- peroxi- 
dase dase ase. 
Per cent. Per cent. Per cent. 
None. | Green....... 10 None. | Green....... 10 None. | Green....... 10 
None. |....-. MO 32.2 10 None. |... -. rb a es 10 None. ]..... dois34 1% 10 
20 | Chlorotic.... 2.5 20 | Chlorotic..-. 5 10 | Chlorotic. - -. 6.6 
I eee dose Got |r) ae) eee do 8 Bosse 2 Cae 6 
40.) 2. 2 do... a7 UM eres do 4.5 6 eee OD ccaccre 7 
ts do.. Sis SRE eet Eh ear es eee | eee et es ee ae eee et) ee 




In the next table is given the peroxidase found in a chlorotic plant 
and in two plants that were once chlorotic, but that had become green 
by treatment with ferrous sulphate. The plants were all growing in a 
sand containing 34 per cent of calcium carbonate, and previous to the 
treatment with ferrous sulphate were equally chlorotic. It will be 
seen that although one of the plants treated with iron contains much 
more peroxidase than the other, they both contain more peroxidase 
than the chlorotic plant. 
Amount of peroxidase in treated and untreated chlorotic plants. 




| Compara- . 
r Appearance tive 
Treatment of plants. Felencrsl Aeaar nn 
peroxidase. 
Wnreatedyys: sssveees eds Chlorotic. . - . 3.3 
Brushed with FeSO4....-.-- Greens. >... 6.6 
FeSO, applied to roots. .--. | Lees GOss2e222 10 
[Bull. 11] 
