ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
441 
The first division of the embryo differs in the Marattiaceae from that 
in typical ferns ; the basal wall, which divides the embryo into two 
nearly equal cells, is almost vertical instead of parallel to the axis of the 
archegone, causing a difference in the position of the organs formed from 
the embryo. This basal wall divides the embryo into an epibasal and a 
hypobasal half, each of which again divides by a median wall vertical 
to the basal wall. The further development is described in detail: 
from the epibasal half originate the cotyledons and the stem ; from the 
hypobasal half the root and the foot. The cotyledon does not spring, as 
in other ferns, from the under side of the prothallium, but grows through 
the prothallium, emerging on its upper side. Neither in the root nor 
in the stem could an apical cell be detected ; the former organ appears 
to be developed from four cells ; the latter from a small-celled meristem. 
Hecistopteris.* — Prof. K. Goebel revives this genus of ferns for 
Gymnogramme pumila, which belongs, not to the Polypodieae, but to the 
Vittarieas, as is shown by the structure of the prothallium and by the 
presence of spicular cells in the epiderm of the leaves. The structure 
previously described as a creeping rhizome consists in reality of roots 
which have a faculty of producing adventitious shoots ; they have a 
true root-cap. The prothallium is irregularly lobed, and is composed of 
a single layer of cells; it possesses the peculiarity of the Vittariese in 
producing elongated adventitious shoots on the margin, which bear 
stalked club-shaped gemmae. From the cells of these gemmae are pro- 
duced new prothallia. No organs of reproduction could be detected on 
the prothallium. 
Muscinese. 
Geothallus, a new Genus of Hepaticse.* — Under the name Geothallus 
tuberosus g. et sp. n., Prof. D. H. Campbell describes a Californian liver- 
wort, which he makes the type of a new genus of the lower Jungerman- 
niaceae, resembling Sphserocarpus in the general structure of the sexual 
organs. The following is the diagnosis : — Plant thalloid, simple or 
dichotomously branched; thallus fleshy, wedge-shaped or nearly orbi- 
cular, partially buried in the earth; margin of thallus divided into 
irregular leaf-like lobes ; similar laminae on the dorsal surface ; ventral 
surface with numerous colourless rhizoids and jointed glandular hairs 
near the apex. Sexual organs scattered over the dorsal surface, each 
surrounded by a sac-like envelope ; sporogone globular, with very short 
seta and bulbous foot ; capsule-wall composed of a single layer of black 
cells ; spores very large, mingled with thin-walled sterile cells. Plant 
perennial by means of tubers developed at the end of the growing 
season. 
Wiesnerella, a new Genus of Marchantiaeeae.J — From Java, Dr. Y. 
Schiffner describes Wiesnerella javanica, the type of a new genus of 
Marchantiaceae, with the following diagnosis : — Fronde parenchymate 
basali et strato aerifero e cameris rhombo-oblongis filis chlorophylliferis 
impletis sedificata, epidermide dorsali poris magnis simplicibus pertusa, 
gernmis nullis, pedunculo carpocephali e frondis sinu anteriore or to, 
* Flora, lxxxii. (1896) pp. 67-75 (7 figs.). 
t Bot. Gazette, xxi. (1896) pp. 9-13 (1 pi.). 
X Oesterr. Bot. Zeitschr., xlvi. (1896) pp. 82-8 (1 pi.). 
