282 BOTANICAL GAZETTE ~ [APRIL 
were traced by laying them on ground glass under water, 
drawing on the ground glass with a lead pencil kept parallel 
with the roots, then transferring to paper by laying the paper 
over the ground glass set in a window. Fig. 12, Nos. g and 
10, shows geotropic curves after the plants had been lying 
horizontally for four 
hours, with roots in water 
at a temperature of 23. 
The rheotropic curves of 
zr to g were made in 
velocities of water rang- 
ing from 100™ to 4oo™ 
per minute, temperature 
of water being 22°; and 
the curves of 5 to S wert 
made in similar circum 
stances except that the 
ides aa Raphanus sativus. Three stagesof yelocities ranged» from 
. 
Be eet a eg rckan ot 1 
16 seedlings, 12 of which had similar curves; @ ute. 
. Shows the seedling before beginning the , revolu- pic curve of 32° at i 
_ tion of the basin of water; 4, after three hours’ from the apex in no. f 
revolution; c¢, after 21 hours’ revolution. The 
F continued to increase DY 
. “of wood; 2, the rubber bands holding the two farther bending in . 
_ strips of blotting paper (3) against the bar of came tissue eVe? when 
wood. ge — 
The temperature was 23.5° in water. this nad b ome 5’ 
- oe distant from the apex, till in no. ¢ 
43°. So also in the roots numbered 5 to 4, it is 
the figures that the initial —— of 15 a3: 
in 5 has in 8 increased to 32° by farther bending in 
tissue, though in the latter case the apex of thes : 
from the root-tip. 
A singular result worthy of note is the app e a 
oe “Foot. of several alternating curves of greater eee? . 
ae Pall giving” to the root an undulating cone 
, ‘ =) in a 73, where a root shows two ater 
