26 BOTANICAL GAZETTE [JANUARY 
growth of lateral roots on the same side. This greater growth 
on the side toward the parchment membrane was not mainly due to 
the effect of the curving of the roots into that position ; but the 
Jateral roots on that side had made a better growth than on the 
opposite side. This behavior recalls the similar results silage 
with varying soils by Nobbe,? Stohmann,* Hoveler,’ and Frank, 
who obtained a greater growth of lateral roots in richer soils. 
Here at last was a result indicating chemotropism of roots. 
Yet the method left much to be desired. With some means to 
insure a greater inequality in chemical composition on the oppo- 
site sides of a root, much better responses might be obtained. 
Il]. DIFFERENT CHEMICALS BROUGHT TO OPPOSITE SIDES OF 
THE ROOTS BY STRIPS OF FILTER PAPER. 
The device next tried was to conduct liquids of different 
composition to the opposite sides of the root by means of narrow 
strips of thin filter paper. The seedlings were suspended from 
a bar of glass fastened horizontally across a damp chamber. In 
the bottom of the chamber were placed two little dishes, one 
containing distilled water, the other Sachs’s culture solution. 
From one liquid a strip of filter paper, 2™ wide, extended 
upward and adhered to one side of the root, while the opposite 
side was covered by a strip from the other liquid. The strips of 
paper were not allowed to touch one another. In some tests, 
the small dishes were placed above the level of the root tips, 
and the paper strips hung downward, touching the flanks of the 
root-tip and then diverging and ending in dishes of water below. 
Every few hours:the strips of paper were adjusted so as to keep 
them in contact with the roots near the tip. In this form of 
experiment nineteen seedlings of Lupinus albus were used, but 
no curves resulted. The objection to this method is found in 
the difficulty of keeping the paper strips in contact with the 
sloping sides of the root-tip. 
3Nopse: Landwirthsch, Versuchsstat. 4: 222. 1862; and 10: 100. 1868. 
*STOHMANN: Jahresbericht iiber die Forschungen der Agriculturchemie 1868-69. 
SHOVELER: Jahrb. Wiss. Bot. 24: 294. 1892. 
® FRANK: Bot. Zeit. 52: 153. 1893. 
