446 BOTANICAL GAZETTE [JUNE 
in those solutions where there was the greatest absorption of 
inorganic nutrients, and while no methods are available to study the 
absorption of this organic compound, it seems justifiable to assume 
that the cultures also absorbed a greater amount of organic constitu- 
ent from the solution, while in other solutions where the absorption 
of nutrients was small the harmfulness of the methyl glycocoll was 
also only slight, indicating that a small amount was absorbed. 
It has been shown in this laboratory and elsewhere that plant 
roots can affect organic substances externally, and it is therefore 
possible that organic substances may also influence the plant itself 
- through this external action; however, in the majority of cases that 
have come under our observation the compounds have been 
absorbed, for in such cases as could be tested they disappeared 
from the solution and had their effects on the plant tops either 
favorably or unfavorably, as the case may be. 
In the case of dihydroxystearic acid the normal metabolism is 
greatly disturbed.!| This is shown by the difference in the absorp- 
tion of the separate nutrients, phosphate, nitrate, and potash, a 
proportionately greater nitrate consumption being evident with 
the plants affected by dihydroxystearic acid. Such a change in 
metabolism could be explained only on the assumption that the 
compound produced a reaction within the plant after absorption 
from the solution. 
The specific effects produced by organic compounds must also be 
taken into consideration. For instance, cumarin produces greatly 
stunted tops, with short, broad leaves and much distorted and 
thickened stems in the case of wheat plants. Quinone, on the 
other hand, produces long, slender, thin plants. The different 
reactions of the plants to these two compounds must be due to the 
direct absorption of the compound accompanied by a disturbed 
metabolism. Moreover, the cumarin-affected plants absorb rela- 
tively more phosphate, the quinone plants relatively more potash.’ 
Furthermore, plants grown in guanidine solutions develop small 
spots of a bleached appearance which grow and spread, producing 
* SCHREINER, O., and Skinner, J. J., Some effects of a harmful organic soil 
epererye9 Bor. GAz. 50:161. 1910. 
——., The toxic action of organic compounds as modified by fertilizer salts. 
Hos Gaz. 54: 31. Ig12 
