60 RIcHARDS AND MacDouGAL: INFLUENCE OF 
showed like discrepancies between the normal and the plants 
grown in CO and gas atmospheres. The ratios of the length of 
the seedling from the seed to the tip of the longest leaves, taken 
from three experiments each of which were the averages of at 
least 8 individuals, is: control 21,in CO 11,in gas 10; of the 
actual main axis itself : control 20, in CO 15, in gas 10 ; and of the 
primary root: control 40, in CO 15, in gas Io. The controls 
showed about twice as many unfolded leaves as did the plants 
grown in CO, while in gas the leaves had barely begun to break 
through their sheaths. 
Buckwheat, sunflower and mustard seedlings exhibited similar 
behavior and the ratios of the length of their hypocotyledonary 
stems and of their primary roots would be nearly the same as the 
forms given above. Squash seedlings showed especially well- 
marked differences in the different gases, the caulicles of the con- 
trols being seven times longer than those in gas, while the roots of 
the former were ten times longer. Those in CO, though a little 
more developed than the ones in gas, were dwarfed as compared — 
with the normal. Naturally the squash is sensitive to diminished 
light so that some etiolation was to be expected, but all were 
under equal light conditions. Perhaps the most striking of all the | 
experiments were those with wheat and rice. The wheat grew but 
little in gas, but fared better in CO. As to the length of the shoot 
to the tip of the longest leaf, we have the following ratios : con-_ 
trol 12, in CO 9, in gas 1; while on comparison of the average — 
length of the several adventitious roots the difference is not $0 
marked: control 2, in CO 1.2, in gas 1. The difference in the 
roots became evident on examining the branches ; secondary root- | 
lets were almost absent in the specimens from the gas, and wef — 
few in those plants grown in CO, but were not only plentifully de- i 
veloped but also branched again in the control experiment. ef 
normal also showed two unfolded leaves with a third just unroll- | 
ing, while in the CO specimens there was barely one, and in those | 
from gas the leaves had hardly broken out of the curiously swollen | 
leaf-sheath. Rice exhibited one of the most prettily graded series. 4 
It grew luxuriantly in the moist atmosphere, and the length of the 
leaf-tip from the seed being 1 in the gas culture, that in CO would 
be about 2 and the control 6, with a nearly similar ratio as ren 
