1921] SCHERTZ—MOTTLING 107 
The fresh leaves (25 gm.) were ground finely with quartz sand, 
placed in the flask, and titrated as suggested by Davisson. 
Aso and SEKINE (3) found that there was about 0o.000,78 per 
cent N in the healthy buds of Sagittaria sagittifolia, when calculated 
on the basis of wet weight, or 7.8 parts N per million of material. 
In mottled Coleus leaves there are 12.9 parts per million, but not a 
detectable amount in green leaves. Boncquet (4) reports the 
presence of nitrite and ammonia in various plants which were 
diseased. The diseases were of the physiological type such as 
curly leaf of sugar beets, curly dwarf of potatoes, mottled leaf of 
potatoes, and mosaic disease of the tobacco. He believes that 
TABLE XIX 
CARBOHYDRATES 
$ | S i Sample TAMS per 
Leaf =e le a e fr | Average a ~~ gd 
A.M. 
EN RIO i Gl go 0.855 1.050 0.932 13.93 
Mottled Asien eee. 0.740 o.820 0.685 0.7 12. 
LU Pia SS ar 1.110 1.090 0.935 T.044 16.84 
P.M, 
Peery eas ieee, 1.435 1.370 1.430 1.412 21.08 
Mottled PE at 0.780 0.850 0.825 0.822 14.17 
pactiled Boa: 1.020 1.040 I.155 1.073 17.30 
nitrogen starvation is brought about by bacterial reduction of the 
nitrates to nitrites and ammonia, after the nitrates have been 
taken up by the roots. The response of the plant to the stimulus, 
he says, is manifested in biochemical, physiological, and morpho- 
logical changes. 
The amount of carbohydrate material in the leaves was esti- 
mated by first boiling (2.5 hours) 10 gm. of the freshly ground 
leaves in 100 cc. of water, to which 1occ. of HCl (sp. gr. 1.125) 
was added. The sugars were then determined as dextrose by the 
BERTRAND (31) volumetric method. The calculations are given as 
grams of dextrose per roo gm. of wet weight. Sugars were deter- 
mined both in the morning and in the evening after a bright day, 
