Boodle . — Anatomy of the Gleicheniaceae . 733 
roots are inserted on the lower and lateral lobes. If one 
follows one of these lobes in the acropetal direction towards 
the insertion of a root, one finds that it becomes more and 
more prominent (Fig. 14, r.\ and finally the outer part of 
the lobe separates as the root-stele. The latter passes out 
slowly, making a very acute angle with the stele until it has 
passed through the pericycle, but as it enters the cortex, it 
usually curves more sharply and soon turns outwards hori- 
zontally, i. e. radially in a transverse plane. 
In G. dichotoma an attempt was made to determine the 
origin of the protoxylems of the root. Though the point 
was not established with certainty, it appeared that two 
protoxylems of the root-trace were supplied from the proto- 
xylem of the xylem-lobe, and that the remaining two originated 
independently, during the passage of the root-trace through 
the cortex. 
Gleichenia, seedling. 
A series of microtome-sections was made of a seedling 
of G. circinata , var. microphylla. Although the soft tissues 
became rather shrunk in the process of embedding, the 
structure could be fairly well determined. 
The primary root has diarch structure. In the region 
of the foot, the root-stele curves towards the prothallus, 
becoming horizontal, and then vertical again. It then still 
has diarch structure, but in passing upwards the protoxylems 
become less evident, and the xylem-plate gradually becomes 
broader. The first leaf-trace, containing only a few tracheides, 
is given off from one of the ends of the xylem, corresponding 
in position to one of the root-protoxylems. The xylem by 
this time has a narrow elliptical outline, but rapidly approaches 
oval form, while one or two parenchymatous cells appear 
amongst the tracheides, soon after the first leaf-trace has 
become free. The first root-trace is attached somewhat 
laterally to the xylem, and shortly afterwards the second 
root-trace is inserted about opposite the first one. The 
parenchyma-cells in the xylem have increased in number, 
