Oct. 15,1925 
Translocation of Food Materials of Wheat Seedlings 739 
high percentage of that element in 3-day roots and plumules with 
proportional loss in the seed. At 6 days the total plant has almost 
the same percentage of nitrogen as the original seeds and after that 
the percentage is always higher. 
Haigh (19) concludes that wheat takes up nitrogen very rapidly 
in the seedling stage. Hoagland (28) has obtained results indicating 
that barley acts in the same way with respect to nitrogen during 
the early growing stages. 
The ash of wheat seedlings changes more rapidly, and the maxi¬ 
mum increase is greater, than the nitrogen or the carbohydrate 
content. The ash of the plumules and roots expressed as per cent 
increase over that in the seed is conspicuous, due to its rate of in¬ 
crease. A 3-day-old root with a dry weight of less than a milligram, 
which is 3 per cent of the original seed, is nearly 12 per cent ash. 
Thus the minerals are deposited in the roots more than fourtimes as 
rapidly as the* other substances. Plumules of the same age are a 
little heavier and contain 11 per cent ash. The close agreement 
in the amount of ash in the roots and plumules indicates that the 
minerals which are absorbed from the soil by the roots are trans¬ 
located at about the rate that they are taken up. The total ash of 
3-day-old plants was 11 per cent greater than that of the original 
seeds. The leaching from the seeds to the soil, if such a loss take 
place in soil as is described by Le Clerc and Breazeale (28) in water 
cultures, must be recovered by the plant at three days, besides the 
total increase which is found, hence the total intake of minerals is 
exceedingly large for this early development. The ash is not used 
from the seed as rapidly as the organic material, and the per cent 
of ash in the seeds falls slightly for nine days, then increases. Nine- 
day-old plumules have as much ash, and the 9-day root nearly as 
much ash, as the original seed, while the dry weight is less than 
one-fourth as great. The percentage of ash in the plumules con¬ 
tinues to increase up to 15 days, when it is nearly 12 per cent, while 
in the roots the maximum percentage is attained at 9 days. Haigh’s 
(19) work indicates a rapid intake of nutrients in the young wheat 
seedling. While Wimmer ( 44 ) found in the first crop of plants— 
that is, those a little larger than the ones used here—8 per cent ash; 
and when ripe the content was 2.33 per cent. The apparent small 
increase in the ash of 25-day-old seeds may be due to the fact that at 
this time much infection of seed has taken place and the lower 
organisms may be adding ash. 
The rapid intake of nitrogen and the mineral elements by the young 
wheat seedling indicates that the plant is able to utilize the largest 
amount of these elements during the first few weeks of growth, and 
that the mineral supply is the limiting factor for the development in 
these young stages. Minerals, Figure 1, are the only substances 
which actually increased as early as the third day. It may be 
mentioned that in common agricultural practice fertilizers with a 
relatively high amount of nitrogen are applied to soils low in fertility 
in order to give the wheat a more rapid early growth. Davidson 
and Le Clerc (8) found that early applications of nitrogen increased 
the yield. Osmotic pressures are given according to the work of 
Harris and Gortner (20 ). 
