1g2t] CHOATE—WHEAT GERMINATION 421 
amino nitrogen. The former determinations were made by the 
Bock and BENEDIcT modification of the Fottn-FARMER pro- 
cedure (3), and this nitrogen is regarded as ‘soluble nitrogen” in 
table V. Determinations were made for amino nitrogen by the 
VAN SLYKE method. The results of these determinations are 
given in table V, from which it is seen that there is a considerable 
amount of amino nitrogen in the ungerminated grain, and that 
during germination this amount increases rapidly, while the increase 
in soluble nitrogen is less rapid. In comparison with these results, 
those obtained by THompson (21) on the Alaska pea seedling are 
of interest. They are as follows: 
PERCENTAGE OF DRY MATERIAL 
Total N Amino N 
PEAS 
DO ic icg ae 4/5 Sick Winey oy bee en we 0.088 
§ U6V9 Oo a 3.28 0.337 
6 days old. RE Garo er eas. 3.48 0.747 
It is also evident from the results given in table V. that micro- 
chemical methods for identifying amino acids are not very satis- 
factory in the case of germinating wheat, probably for several 
reasons. The amino acids may be present in such small amounts 
that, although totaling an appreciable quantity, they cannot be 
detected individually; they may be those for which no satisfactory 
microchemical test has yet been found; or, as suggested earlier, 
other material present may prevent normal reactions from 
occurring. In the case of wheat such substances as storage 
proteins might easily interfere with the crystallization of the 
amino acids and so prevent their identification. 
Summary 
1. The principal storage carbohydrate of Marquis wheat is 
starch in the endosperm. A small amount of sucrose is also 
present in the endosperm and embryo. 
2. The first noticeable chemical change during germination is 
the appearance in the scutellum and coleorhiza of dextrin, and in 
the root cap of starch. These substances appear simultaneously 
after about ten hours in the germinator (16°-20°C.). Later 
dextrin appears in the coleoptile and plumule. 
