374 BOTANICAL GAZETTE [DECEMBER 
greatest abundance on opposite sides of the nucleus, foreshadow- 
ing the development of a bipolar spindle. 
Usually one pole is formed considerably in advance of the 
other; and in cells cut parallel to their long axis, it can be seen 
that the first pole (the greatest accumulation of kinoplasm) is 
on the side of the nucleus remote from the chromatic mass of 
synapsis. _ 
The spindle is bipolar from the beginning. Némec’s (10) 
generalization, therefore, that sporogenous cells as compared 
with vegetative cells are characterized by their spindles passing 
through a multipolar phase, does not hold good of Osmunda. 
The fully formed spindle shows no distinction of central and 
mantle fibers, and no bodies which can be interpreted as centro- 
spheres ; all the fibers run from pole to pole. 
The dissolution of the nuclear membrane is attended by a 
sudden narrowing of the spindle anda corresponding increase 
in length. 
During the anaphase new (secondary) fibers, not to be con- 
founded with mantle fibers, are put forth about the poles and 
meet in the equatorial region of the cell. 
In the late anaphase the primary fibers, and soon after them 
the secondary fibers, begin to disintegrate, taking the appearance 
of beaded threads, and then of granules; at this time all of the 
stainable cytoplasm of the cell appears granular in texture. 
The spindles of the second division at first have their axes 
parallel to the first cell plate. They are constructed out of 
the granular products arising from the disintegration of the first 
spindle. 
The phenomena of the second spindles exactly repeat those 
of the first, except that four secondary spindles are formed by 
the union of the secondary fibers put forth during the anaphase. 
The primary spindles become rotated about each other so 4 
to bring the four daughter nuclei into the tetrahedral arrangement. 
Cell plates are formed across the six spindles (two primary 
and four secondary), and in connection with them the separating 
walls of the spores are laid down. 
