102 BOTANICAL GAZETTE 
cylindrical strand composed of reduced phloem and xylem, surrounded 
by a mass of thick-walled sclerenchyma fibers. When the paren- 
chymatous cortex is removed, the sclerenchymatous axis remains as 
a tough elastic fiber, which serves as a packing in upholstery. Th 
so-called curing process is a means of eliminating the parenchyma. 
One method largely employed is that of burying the moss in trenches 
or pits, allowing it to remain till the cortex is dead and in a condition 
to be removed easily. : 
DEVELOPMENT OF THE EMBRYO SAC. a 
The primordia of the ovules arise on the innermost wall of each 
loculus of the tricarpellate, superior ovary. By a one-sided growth 
each primordium becomes bent toward the base of the ovary, develop- 
ing into the anatropous type of ovule. When the bending has reached 
an angle of about 90°, the nucellus appears as a hemispherical mass 
of cells, at the base of which can be seen the beginning of the inner 
integument. Imbedded under two layers of nucellus cells, the single 
archesporial cell becomes differentiated in the usual way, by its 
slightly larger size and greater staining capacity ( fig. 2). As th 
ovule increases in size, the nucellus elongates, the outer integument 
appears, and the archesporial cell enlarges considerably, especially 
in length. There is no parietal cell formed, but by multiplicatio 
of cells the nucellus over the archesporial cell forms an additional | 
layer, making three (fig. 3). The archesporial cell is now 
elongated, and occupies the central region of the nucellus. I : 
filled with granular, longitudinally-striated cytoplasm, and has 
relatively large nucleus. The first and second divisions of | 
nucleus probably give rise to the gametophyte generation. 
more than one-third the length of the cell (fig. 4). ‘The chromosom 
were short, and closely crowded at the equatorial plate. i 
ditions were altogether unfavorable for ascertaining their nut 
on account of the small size of the figure. The number, howev 
was definitely made out from the second division of the pollen pa 
cells, and was found to be sixteen. A protracted search failed 2 
yield a nuclear figure which definitely showed the chromosome | 
number in the sporophyte, though considerably over sixteen — 
observed. 
