166 BOTANICAL GAZETTE [SEPTEMBER 
an earlier paper, and the reader is referred to this for a full explana- 
tion of the use of the triangular diagram and the results obtained by 
growing seedling wheat in these various culture solutions without the 
presence of any added harmful substance.’ Wheat seedlings were 
then grown in these various cultures and observations made in regard 
to general development, the effect on the root growth and appearance, 
- and on root oxidation, and at the termination of the experiment the 
green weight of the plants was taken. The solutions were changed 
every three days and an analysis made, the phosphate, nitrate, 
and potash being determined, thus giving the concentration of 
these elements and their ratios existing at the end of every three- 
day period for comparison with the original concentration and 
ratio. This changing of the solutions was kept up for twenty- 
four days, thus making eight changes. 
In the present work a triangle of solution cultures similar t0 
the one described in the previous paper was set up, with the differ- 
ence that 50 parts per million of dihydroxystearic acid were present 
in each culture. This set of cultures grew from April 2 to April 26. 
The set without the dihydroxystearic acid grew from February 26 
to March 21. While these two sets are not strictly comparable, 
owing to the fact that they were grown at different times, thoug 
under very similar greenhouse conditions and for the same length 
of time as well as in the same time of year, one closely following 
the other, the results show, nevertheless, very strikingly the effect 
of dihydroxystearic acid, and are duplicated or substantiated by 
two further experiments in which the sets were grown simultan® 
ously. 
The analytical results, however, were not so complete in these. 
later tests, owing to the inability to handle the 396 separate deter 
minations necessary every three days. The results given in this 
paper, therefore, are largely based on the first set, for the reason 
that the analytical results were more complete than in the other 
sets mentioned, 
The difference between the cultures containing the dihydroxy- 
stearic acid and those without this substance was very markedy 
5 SCHREINER, O., and Sxmner, J. J., Ratio of phosphate, nitrate, and pot 
on absorption and growth. Bot. GazeTrEe 50:1. 1910. - 
eas 
Bn SEN aera i dha AT cel eters SR 5) See ARI 
