408 BOTANICAL GAZETTE [JUNE 
zone immediately inside of the passive outer cortex. None of 
these changes appear in the terminal portion of the root. 
Besides, there exists another difference, noticeable even in the 
‘ _ primary root, but more pronounced in older plants. In that 
portion where the cells do not undergo any considerable change 
of form and size, the cortical parenchyma is densely filled with 4 
starch grains; but in the basal region, as far as the parenchyma 3 
exhibits strong activity of contraction, starch grains are entirely : 
absent. 
The contraction of the cortical parenchyma causes changes 
also in the passive tissues, inside as well as outside of it. Inside 
it leaves very characteristic traces in the endodermis. This 
tissue behaves like the elements of the central cylinder, becom- 
ing passively contracted in longitudinal direction. In the begin- 
_ Ming, the cell-walls of the endodermis are straight and show 
_ Nothing exceptional in their outer form, and so they remain in 
_ the end-portion of the root and in the branches throughout rang 
_ But in the basal portion, as far as contraction occurs, the rad 
longiti inal walls of the endodermis become marked by - 2 
undulation running longitudinally. This undulation, here as 1 
other Species, corresponds to the dark spot, which is observed 
On the same wall on the cross-section. The undulation or wavy | 
folding of the membrane is most pronounced near the root-base, 
strong t shortening takes place, and diminishes toward - 
d, being entirely absent near the tip. 
Quite a similar phenomenon is to be noticed, outside of te 
‘Cortex, in the hypodermis. Also in this tissue, the ee . 
branes of which are quite straight at the beginning, as far # _ 
Contraction reaches, an undulation of the radial-lot 
lulation of the cell-wall in both endodermis and h 
becomes fixed and remains nearly unaltered 
_these tissues in old roots from the adheri 
after the appearance of the undulation, the 
