THE RHEOTROPISM OF ROOTS 359 
geotropism. In my own study some experiments 
ein which the effect of gravitation was sought to be 
ti using the centrifuge revolving with vertical disk 
_ The plan is wholly feasible, but in my work was 
ts attain only a small deviation from the jens ee 
,and some go°, the last seeming to overcome their 
S When the definitive angle is attained by a 
n hile the water stream still ea 
nce of the geotropic counter-curve is explained 
ing that the resultant position of equilibrium for roots © 
tropism and rheotropism are competing is different 
m= from what it is in the part of the root farther 
difference in position of equilibrium for the two ae 
le root is due to the extent of both the sensitive and 2 
mes. The first curve in ordinary age — 
‘oot beyond the resultant position of equilib: 
ale being confined to the apical aaa: 
-k is, by the sinking of the sensory zone, released — . 
ae its impulse to bend downward. — As there os 
iment a continuous rising of the part of the root 
the apical 2™™ as we must | assume 
s owth goes on, 
t st 8 in this 
: thin 2™" of the apex, and the latter three . 
from the apex. oe 
sent paper has given viene. Ae 
of at least 15™ of the apex of the ro 
f water es ageinet, the Ce : 
