Oct. 15, 1925 
Translocation of Food Materials of Wheat Seedlings 741 
ing. Yuncker (46) found the maximum photosynthesis took place 
in the corn plant about noon. These two factors would tend to 
increase the depression of the freezing point of stages effected by 
transpiration and photosynthesis if the plants were collected during 
the middle ol the day and bring about less difference in the 2-day- 
old stage and later stages. These conditions could not be controlled 
from day to day; therefore it was thought advisable to avoid that 
period. The morning collections of material obviously give more 
accurate results on the plant’s composition. 
SUMMARY 
During the early stages of the germination of the wheat seedling, 
the ether extract disappears from the seed more slowly than the 
carbohydrates or nitrogen, and accumulates in the plumules and 
roots more slowly than any other food material investigated. 
The small amount of sugars normally found in the wheat kernel 
increases rapidly in the seed during the first six days of germination 
when nearly three-fourths of the starch has been used. After six 
days, the amount of sugar decreases. The sugars are translocated 
to the plumules and roots more rapidly than they can be used, while 
there is a supply of starch in the seed, but after nine days there re¬ 
mains approximately 1 per cent of the original starch; the sugars in 
the axes decrease sharply. These plants are dependent upon their 
photosynthetic powers for carbohydrates after 12 days. Under the 
conditions of this experiment, the embryo seemed to depend on the 
endosperm for about six days for its carbohydrate supply. During 
the period between 6 and 12 days the plant seems to become inde¬ 
pendent. 
The hemicelluloses appear to be of little importance to the develop¬ 
ing plant. The plumules and radicles show no marked difference in 
the percentage of acid hydrolyzable materials during the germination 
period. 
Nitrogen is translocated rapidly in the three-day seedling, but 
after that the percentage remains constant in the axes. The nitrogen 
content of the seed decreases in proportion to the weight the first 
nine days; after that a more rapid loss occurs. 
Wheat seedlings require proportionally larger quantities of minerals 
than any other food material. The maximum ash content of plumules 
and radicles is reached in 12 to 15 days. The roots appear to take 
in minerals more rapidly than they are translocated in the early 
stages of germination. 
The concentration of the cell sap decreases from 2 days to 12 days, 
after which an increase takes place. This follows closely the changes 
in water, sugar, and ash contents of the plant. No elaborate method 
of extracting the sap was found necessary. 
LITERATURE CITED 
(1) Bakke, A. L. 
1918. determination of wilting. Bot. Gaz. 66: 81-116, illus. 
(2) Brenchley, W. E., and Hall, A. D. 
1909. THE DEVELOPMENT OF THE GRAIN OF WHEAT. Jour. Agr. Sci. 3: 
195-217, illus. 
(3) Brown, H. T., and Morris, G. H. 
1890. RESEARCHES ON THE GERMINATION OF SOME OF THE GRAMINEA3. 
part i. Jour. Chem. Soc. [London] 57: 458-528, illus. 
73704—26f—-4 
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CmAL 'WESTIGWONS 
