512 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Leaf of Fissidens.* * * § — From the nerve-structure of the leaf of Fissi- 
dens , Mr. E. S. Salmon argues in favour of Bobt. Brown’s explanation of 
the peculiar form of the leaf, viz. that the sheathing part alone is the 
true leaf, all the rest — usually called the superior and the inferior 
laminae — being an outgrowth from the back of the leaf, in which a nerve 
has been developed. The author accepts Mitten’s classification, placing 
the genera Fissidens , Bryoxijphium, Sorapilla, and Eustichia together in 
the tribe Skitophylleae. 
Sporogone! of Hepaticse.f — Herr J. Andreas 'gives an exhaustive 
account of the structure of the wall of the sporogone and the mode of 
dehiscence in the Marchantieae and the J ungermanniaceae. In these 
two families, in which the capsule must be regarded as a typical sporo- 
gone, it remains (except in the Operculatae) until ripe enclosed by the 
archegone as a calyptra, which it only breaks through when ripe by 
the elongation of the stalk, the spores then escaping immediately. In 
the Operculatae the sporogone breaks through the calyptra before it is 
ripe. The sporogone varies greatly in size and form, as well as in 
thickness, and in the number of layers of which it is composed. It is 
distinguished by the almost universal thickenings in its epidermal cells. 
The mode of dehiscence also varies greatly. On these various points 
three types may be distinguished, viz. : — 
1. The Marchantiese. The wall of the capsule is always composed 
of a single layer of cells, except at the apex. Three different modes 
of dehiscence are described in detail : — (1) in Lunularia and Cyatho- 
dium; (2) in Fegatella and Dumortiera ; (3) in Duvalia and Grimaldia. 
As regards the structure of the wall, the genera are arranged under 
four different tyj>es, which are described in detail in a number of 
species. 
2. The anacrogynous Jungermanniacese. The structure of the wall 
of the sporogone varies very greatly in many different directions. Jt 
may be composed of a single or of many layers of cells. Seven of the 
species examined, belonging to four genera, have elaterophores. 
3. The acrogynous Jungermanniacese. The structure of the wall of 
the sporogone displays much greater uniformity ; it is always composed 
of several (2-8) layers of cells. The variations refer to the number 
of layers and to the development of the thickenings in the layer which 
bounds the spore-cavity. The author classes the genera under four types, 
— those of Jungermannia, Fegatella, Symphyogyna, and the Operculatae. 
Cleveidese.J — Graf zu Solms-Laubach discusses at length the re- 
lations!^) to one another of the three genera of this family of Mar- 
chantiaceae, Clevea, Peltolepis, and Sauteria , and their geographical 
distribution. 
Wettsteinia, a new genus of Hepaticae.§ — Dr. Y. Schiffner iden- 
tifies van der Sande Lacoste’s two Indo-Malayan species of Plagiochila , 
P. inversa and scdbra , but constitutes them, under the name Wettsteinia 
inversa, the type of a new genus, distinguished from Plagiochila by 
* Ann. of Bot., xiii. (1899) pp. 103-30 (3 pis.), 
t Flora, Ixxxvi. (1899) pp. 162-213 (1 pi. and 29 figs.), 
j Bot. Ztg., lvii. (1899) 1*® Abth., pp. 15-37. 
§ Ann. Jard. Bot. Buitenzorg, 1898, 2 me Suppl. pp. 39-46. 
