348 
Ït is a remarkable feature of the root bundle that the phloems 
meet in the middle, showing exactly the reverse condition from 
that common to the roots of other plants and in the stem 
bundles of the Lycopodiaceae, where the xylems meet in the 
middle of the bundle. 
In the upper part of the root the parenchyma cells are filled 
with starch and the vascular bundle is suspended in the par- 
enchyma at different corners by long starchfilled cells. The 
starch parenchyma is not continuous, however. In many cross 
sections it proved to be almost 
entirely absent. This curious phe- 
nomenon goes parallel with the 
wrinkles which occur in the upper 
parts of the roots, near the surface 
(Fig. 17 and 18). The starch oc- 
curs only in the parenchyma im- 
mediately under the convex side 
of the wrinkle; in the concave 
parts no starch can be found. 
Fig. 17 shows the situation in a 
longitudinal section through the 
upper part of a root. The sec- 
tion is not exactly median, but the 
parenchyma cells, surrounding 
the vascular bundle, are in a wrinkled condition themselves. 
Evidently we have here a case of root contraction (de Vries, 39). 
This is, so far as we are aware, the first case of real root con- 
traction recorded in cryptogamous roots. Fig. 18 shows the 
condition in a median longitudinal section, with higher magni- 
fication. The wrinkling of the cell walls is quite obvious. 
De Vries found the seat of the root contraction situated in 
the root parenchyma. This is in perfect agreement with this 
case; the decrease in turgor in the wrinkled parenchyma cells 
probably prevents these from manufacturing starch. 
We see also the remarkable fact that some of the tracheids 
Fig. 19. 
