ae 
_ Naiadaceae 
362 
BOTANICAL GAZETTE 
bey 
As to the nature of the rheotropic stimulus, there is no direct _ 
evidence. 
I still incline to the notion of pressure, as expressed 
in my paper before the American Association for the Advance- 
ment of Science in 1896. As yet, however, no one has demon- — 
strated in the roots of plants any kind of a response to pressure. 
Il. TABULATION OF SPECIES EMPLOYED AND THEIR RHEOTROPIC BEHAVIOR. 
Family 
Species 
Gramineae ....—. .... 
ieee 2 
Liliaceae 20.02. 0.. 
Zea mays Lc Vellow dent's. o250 = 
o eet colin Si oahee ae 
us . corn.... 
vulgare L...... 
anadensis M : 
otamogeton pefoias L 
Allium 
“ee 
ah 
I 
: : 
en sania Pe Ss ee 
E 
I 
f 
m cepa L 
cronies WARS ok 
tivum | 
Glycine “hispida Maxim... 20120007 
‘Dolichos lablab L.... 
Lathyrus odoratus 
‘Pielianthus annuus Eki. ek 
eee ee ee ee 
ee ole © . 
ee a eee we 
Rheotropic behavior 
———n 
Feebly se sensitive 
