332 BOTANICAL GAZETTE [NOVEMBER 
used Orchis as the only type. At present, therefore, our knowl- 
edge of the details in this group is very meager.® 
In Convallaria the early stages in the development of the 
anther are not so easily understood as are those of the dicotyle- 
dons; but after the investigation of a large number of prepara- 
tions it seems probable that the following is the proper inter- 
pretation, not alone for Convallaria but also for many other 
-monocotyledons. The earliest stages obtained show in cross- 
section a four-angled anther with a radial row of cells at each 
angle, which apparently result from the division of a single 
hypodermal cell. 
The condition at this stage is represented in fig. I. The 
innermost cell, the primary archesporial cell, very soon divides 
in various directions until a considerable mass of tissue 'S 
formed. This division takes place very early, so that the final 
number of archesporial cells is formed even before the anther 
has become obviously lobed. At this stage it is only with com 
siderable difficulty that the archesporium can be distinguished 
from the wall (fig. 2). The original radial row of cells, 
descendants of the primary hypodermal cell, may often be rec- 
ognized for a considerable time after they are first formed, vo 
in some cases one or two cells on either side may also divide 
several times in a radial direction. The greater portion of the 
wall, however, is derived from a few irregular divisions of o 
cells at each side of the archesporium, while the epidermis #6 
the same time increased by a few anticlinal divisions. In sat 
to this the cells between the archesporium and the connect 
may also undergo a few radial divisions. As 4 result the 
cells in the older anthers do not stand in distinct radial se 
as in the dicotyledons, simply because they were not all web 
by radial division; but, notwithstanding this, there are 4 
6 While in press the following papers have appeared: © ar cas pil 
GUIGNARD, L.— Le développement du pollen et la réduction dans le Nava 
Arch. d’anat. Microscop. 2:455. 1899. . an. 1899- 
CALDWELL, O.—- Life history of Lemna minor. BOT. Gaz. 27 +37: ‘erospores of 
FULLMER, E. L.— The development of the microsporang!a and mi 
Hemerocallis fulva. Bot. GAz. 28:81. 1899. 
