1918] OTTLEY—IMPATIENS 291 
and its allies rather than by the more specialized groups.” Bal- 
saminaceae, one of the higher groups of the Archichlamydeae, 
shows complete suppression of parietal tissue in J. Sultani; in 
I. pallida, however, Miss Rairr (37) describes a parietal cell, 
but her illustrations are not very conclusive. 
From the first the megaspore mother cell is the only hypodermal 
cell at the apex of the ovule. It is surrounded by the epidermis 
of the nucellus at its sides and apex, and is bounded by several 
nucellar cells at its base (fig. 2). The cell is slightly longer than 
wide and extends almost to the plane of insertion of the inner 
integument. It keeps pace with the growth of the ovule and con- 
tinues to occupy all of the nucellus within the epidermis except 
in the chalazal region. As growth continues it changes from a 
broad cell to a long narrow one (figs. 2-4, 6). 
The nucleus of the megaspore mother cell contains one nucleolus 
which at first is separated from the chromatic network by a clear 
area (fig. 2). As division is initiated, the chromatic reticulum 
forms a more or less complete spirem, separates from the nuclear 
membrane, collects about the nucleolus, and enters the synaptic 
stage (figs. 3, 4). On recovery from synapsis the spirem spreads 
out into the nuclear cavity and very soon exhibits the second con- 
traction stage (fig. 5) similar to that which has been described for 
Lilium and several other angiosperms by ALLEN (2), MoTTIER (32), 
and others. According to OVERTON (35), this phenomenon does 
not occur among the majority of the angiosperms. 
During this stage the spirem is thick, and at places uneven and 
massed. Here and there, in the less condensed areas, light streaks 
show, suggesting either a longitudinal splitting of a single spirem 
or an approximation of two. The contracted spirem is in contact 
with the nuclear membrane at several points, but the greater 
amount of the chromatic material is near the nucleolus at the 
center of the nucleus. At this time the nucleus is near the micro- 
pylar end of the megaspore mother cell. About midway between 
it and the chalazal end are numerous fibers with blue staining dots 
scattered among them. This characteristic has been observed in 
several megaspore mother cells, but its significance was not deter- 
mined. These fibers played no apparent réle in the formation 
