June, 1910.] 
Winter -Buds of Spirodela. 
181 
The ordinary Fragile Bladder Fern grows in abundance upon 
these rocks. A hasty glance revealed the fact that it differed 
very materially from the ordinary form. The apexes of the frond 
and the tips of the pinnae are branched two to four times, acumi- 
nate, obtuse or emarginate. 
The plant grows plentifully in the partially shaded ravine 
and the differences from the normal type of frond seem to warrant 
the name: 
Cystopteris fragilis (L.) Bernh. var. cristata Hopkins, var. nov. 
Apex of frond branched, the branches often dividing again; 
obtuse or acuminate, pinnae linear, lanceolate, broadly triangular, 
acuminate, acute or obtuse often branching into two or more irre- 
gular segments; in part on sandstone rocks, Woodworth’s 
Glenn, Portage County, Ohio. (Fig. 2). 
Pittsburgh High School. 
WINTER-BUDS OF SPIRODELA POLYRHIZA (L.). 
V. Sterki. 
Last summer and fall, I brought home several kinds of 
“duckweeds,” and kept them in aquaria, some of the latter being 
small tumblers. During September and October it was noticed 
that there were numerous small disks, or links, partly free, partly 
connected with Spirodela plants. They were flat, short-elliptical 
or oblong, or nearly circular, of about one to two mm. diameter, 
of a deep green color (darker than the spirodela disks), always 
rootless, without any visible venation and with a small, sharply 
defined, crescent-shaped, whitish to brownish hilum at the margin. 
Microscopic examination, made in February, showed them to 
have stomata on the upper surface and a slight but distinct 
purplish hue on the lower, inside of the epidermis. 
With the approach of winter, the Spirodela plants faded 
and died, but these small bodies kept fresh and green, and most 
of them sank to the bottom. Some, however, were kept floating 
by the dead disks, now little more than skeletons. Some were 
seen as late as February, each being held between the two epi- 
dermal layers of its parent disk, near the hilum, partly emerging 
from the margin. Several score were in a small tumbler aqua- 
rium, near a window but not reached by direct sunlight until the 
end of winter. During the latter part of January, and up to 
the present it was noticed that each had a small gas bubble on 
its upper surface, probably oxygen, and some were raised to the 
surface by the same and kept floating. Many of them are now 
sprouting, at the hilum, while others are still at the bottom, 
unchanged. Another such small aquarium, with Lemna tri- 
