252 BOTANICAL GAZETTE : [ocTOBER 
the high photosynthetic activity during the day and the lack of 
photosynthesis and a very active translocation of starch during 
the hours of darkness. In this work a study of the sections of 
leaves from healthy trees removed early in the morning and in 
mid-afternoon was made for comparison with leaves from diseased 
trees which were collected at the same time. In the leaves from 
normal healthy trees it was found that there was very little or no 
starch in the leaves during the morning hours, and an abundance 
during the afternoon (figs. 1, 2.) This of course was to be expected, 
and indicated that the photosynthetic and translocation processes 
were normal and active on the day that the material was collected. 
In some instances a small amount of starch was found in the cells 
in the morning in the immediate vicinity of the veins (figs. 3, 4). 
This was no doubt due to incomplete translocation and may possibly 
indicate a slightly abnormal condition. 
Leaves were collected from the varieties known as Samay; Hiley, 
and Chinese cling, which were affected with yellows. In those in 
which the disease was severe, the amount of starch in the sections 
from leaves cut in the morning was almost as great'as the amount 
found in leaves cut in the afternoon, indicating little or no trans- 
location of the carbohydrates (figs. 5, 6). The amount of starch, 
however, was not as great in either case as in the healthy Elberta 
(fig. 2) in the afternoon, but was greater than in the healthy Hiley 
(fig. 4). These differences in the amount of starch in the individual 
trees may be due to a difference in the physiological activities of 
the trees, and may possibly be accounted for by differences in 
variety, age, or other factors. . 
A morning section of a Chinese cling affected with yellows (fig. 7) _ 
compared with a morning section of a healthy tree of the same 
variety showed a much larger amount of starch in the leaf from 
the diseased tree than in the leaf from the healthy tree, indicating 
not only a reduced translocation of carbohydrates but also an 
accumulation of these products. There was very little difference, 
however, between the amount of carbohydrates found in the 
morning and afternoon sections from diseased trees (figs. 7, 8). 
The little peach was studied on Elberta and Hiley. The 
amount of starch was practically the same in the sections from 
