28 A. Henfrey on the Higher Cryptogamous Plants. 
The first change in this sac is the appearance of a nucleus} 
from this cells are developed representing the suspensor of the 
embryo. The cells of the suspensor multiply and form the pro- 
cess which penetrates down into the parenchyma of the cavity of 
the spore; at the lower end may be detected the embryo, a mi 
nutely celiular body. Dr. Mettenins never saw the embryo pro- 
duced in the embryo-sac before the suspensor had broken through 
the bottom of it to penetrate the parenchyma of the spore-cell; 
it was always within this parenchyma and attached to the end of 
the suspensor. In this point he is decidedly opposed to Hofmeis- 
ter, who states that the embryo originates in the embryo-sae, 
whence a young embryo attached to its suspensor may easily be 
extracted from the spore. 
The part of the embryo opposite to the point of attachment of 
the suspensor corresponds to the first axis of the Rhizocarpee, 
which never breaks out from the spore-cell in Selaginella ; it 
pushes back the loose parenchyma of the spore-cell as it becomes 
developed, and when completely formed, is surrounded by a thin 
coat composed of several layers of the parenchymatous cells much 
compressed, enclosed in the still existing inner coat of the spore. 
On one side of the point of attachment of the suspensor the em- 
bryo grows out towards the point where the spore-cell has been 
ruptured, thus apparently in a direction completely opposite to the 
end of the axis. As it enlarges it produces in this situation the 
leafy stem growing upwards, and the adventitious root turnin 
downwards. The pro-embryo is at first distended like a sac, and 
finally broken through on the one side by the first leaf, on the 
other by the adventitious root; upon it may be observed the nu- 
merous abortive ovules, with their embryo-sacs filled with yellow 
contents; part of its cells grow out into radical hairs: 3 
tenius several times saw two young plants produced from one 
spore; the ends of their axes lay close together, and separa 
inside the cavity of the spore. No account is here given of the 
characters exhibited by the small spores, or of anything like @ 
process of fertilization; yet we have indicated in the foregoing 
description of the so-called ovules, a clear analogy between these 
bodies and the so-called ovules of the Ferns and Rhizocarpe®: 
These points will be referred to again at the close of the repor 
In a review of Dr. Mercklin’s essay on the reproduction of the 
Ferns, in the Flora,* Hofineister states that spiral filaments are 
produced from the small spores of Selaginella, but does not st@ 
that he has seen them, or give any authority. . 
Isottacee.—The spores of the [soétes lacustris are of two kinds, 
analogous to those of the Lycopodiacee ; both kinds being pro 
duced in sporangia imbedded in the bases of the leaves, but the 
ee 
* Flora, 1850, p. 700. 
