1902] ORGANS OF SOME CALIFORNIAN LILIACEAE 417 
dermis with feeble V-thickenings, and a narrow cortex. They 
show nothing peculiar, and are purely nutritive. 
_ The daughter tubers, however, behave differently. After 
faving formed two or three thin roots of the structure of those 
jist mentioned, each of them sends out one thick, fleshy, con- 
trctile root (fig. 75, 7). This root grows ina strictly horizon- 
tl direction, keeping in its whole extent not far from the surface 
thesoil. It reaches over 20™ in length and 3 to 4™™ in diam- 
tter, tapering in its terminal portion to 1™ in thickness. Its 
central cylinder is 5-archic with a central vessel, and the cortex 
very thick, 
It is semi-transparent, and it can be seen that the course of 
the central strand is not straight, but irregularly undulated and 
(fig. 16). Such a course of the central strand is very 
mon in monocotyledons. Also in this case it seems to 
«foto much a necessary consequence of the shortening itself, — 
@ consequence of the irregular manner in which the active ao 
“al cells change their form. While in other roots the cortex 
: a all around the central _ in ye _ : 
ite on different sides bE a cual 4. This 
po emenon, and the manner in which it is 
01 
f the hypodermis, become aii a 
tinkled to an extent of A from the base. No zo! 
