348 BOTANICAL GAZETTE [NOVEMBER 
the root rudiment appears to come into contact with the cell walls 
at intervals only.. This is indicated in sections by the presence 
of a cavity about the root tip, the bulb parenchyma being separated 
from the root itself by a space in which there appear no cell walls. : 
In the cells at a little distance from the line of advance of the root, 
scattered starch grains appear, and the normal starch content | 
remains in the bulb parenchyma farther from the root cluster | 
(text fig. 2). It appears that the starch is first removed from the 
cells in the path of the advancing root rudiments, then as the root j 
is organized and grows forward, the cells themselves are disinte- | 
grated, leaving a clear pocket immediately about the conical end i 
of the root. Only at the ) 
: ¥ Se Sete 
RES ee Ctetr ts ee ee 
sides of these cavities were 
there any flattened cells, 
as if contact had occurred 
between the root tissue 
and the surrounding par- 
enchyma. But as the root 
issues from the base into 
the soil, there is a collar of 
cells about the base, which 
constricts the root at this 
point to.a slight degree. 
Fic. 2.—Base of bulb, showing inception of The number of roots in- 
etna eens F002 creases with the age of the 
bulb, in large flowering individuals reaching 30 or 40. These all die 
at the close of the season, and a new set is formed for the next year, 
even if the new bulb is developed in situ. The roots have no con- 
tractile cells, and act only as absorbing organs; the shape of the 
bulb helps to anchor the plant in place. Root hairs are produced 
in abundance in a moist chamber, or in nature on those parts of a 
root which may pass through an air space in the soil. Where the 
soil is in close contact with the root, the root hairs are inconspicu- 
ous or undeveloped (in this connection see 8, p. 146). The mer 
stem tissue from which the roots arise continues to form new root 
rudiments for some time after the main supply of roots is formed. 
Thus a new crop of roots may be formed after the already developed 
