36 Gibbs . — Notes on the Development and Structure of 
if it were constantly bein^ 
^-'"per. t. 
-ax. r. 
Fig. 1. 
„ per. 1 
Figs. 1-3. The dotted lines represent the cell layers, and 
when interrupted show digestion of the same. 
drained of contents. There is no peripheral 
solution of tissue, as is the 
case in the vicinity of the basal 
suspensor cell, the endosperm 
layer merely consisting of pas- 
sage cells. The entire absence 
of any other form of secretory 
tissue can only lead to the con- 
clusion that the endosperm in 
this case is the medium through 
which the starch stored in the 
perisperm is made available 
for the growing embryo. 
The Axile Cells of the 
Nucellus and the Perisperm . 
Before fertilization, continual 
vertical growth in the basal 
region of the nucellus results 
in an increase of the axile rows 
(ax. r. Text-figs. 1-3). Anti- 
clinal cell division of the peri- 
pheral layers (per. 1 . Text-figs. 
1-3), which from the earliest 
stages of development, is less 
active on one side than the 
other, now ceases altogether 
on the lower side, and the 
embryo-sac is thus forced from 
a horizontal to a more or less 
vertical position, by the cam- 
pylotropous curvature of the 
nucellus characteristic of the 
order. 
The axile cells are in serial 
connexion with the chalazal 
cells, and after fertilization two 
or three of the basal rows 
become vacuolated and the 
nuclei migrate to the walls, 
which cuticularize (b. c. Text- 
fig. 4, p. 38). These cells form 
a band across the chalaza con- 
necting up on each side with 
_ _ ax. r. 
Fig. a. 
per. 1. 
L—.ax. r. 
Fig. 3. 
