IIo BOTANICAL GAZETTE [FEBRUARY 
APPLEMAN (1), using ro cc. of dioxogen as the hydrogen peroxide 
and suspending the plant material in 10 cc. of water. Tables XXIII 
and XXIV show the cubic centimeters of oxygen liberated per 
o.5 gm. of fresh weight of leaves at 25°C. during 10 minutes of 
activity. Table XXIII shows that the catalase activity gradually 
TABLE XXIII 
EFFECT OF AGE OF LEAF ON GATALASE ACTIVITY 
OXYGEN LIBERATED 
BR aes OSes nc eared 4 aula Second pair of leaves 
OF eee ae i ee Third pair of leaves 
BA Os ere cee Fourth pair of leaves 
MPG ics Wap et Cie sc ene ede ess ko Fifth pair of leav 
TA OR Cie ve ei er hehe pera ei: Sixth pair of leaves 
BURP eo oe Seventh pair of leaves 
SPOT cys ee es ea ee ks Eighth pair of leaves 
* Leaves still green. 
t Leaves half mottled. 
increased and reached a maximum in the third or fourth pair of 
leaves, and then decreased gradually until the leaf mottled. With 
mottling of the leaf it was noticed that the catalase activity dropped 
enormously. 
From table XXIV it is + boident that as the leaves mottled the 
catalase activity decreased greatly, even reaching a value of less 
TABLE XXIV 
COMPARISON OF CATALASE IN GREEN AND MOTTLED LEAVES 
COMPLETELY MOTTLED GREEN 
6.3 103.0 
10.0 95.0 
8.0 990.0 
than 1/10 that of the healthy leaves. The mottled leaves were 
taken from the plant 3 or 4 nodes below the green ones, and there- 
fore age would be a factor, but it is not sufficient to account for the 
enormous decrease in the catalase activity. 
An analysis of the leaves was made to determine the amount of 
nitrogen and phosphates in the F,, F,, and F, of the three types of 
leaves. Each morning the leaves were collected until 80 gm. was 
obtained for each sample; the leaves as collected were preserved 
in 95 per cent alcohol in ground glass stoppered, wide-mouthed 
bottles, and kept there until needed for analysis. An extraction 
