364 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Muscineae. 
Rhizome and Stem of Mosses.* — M. E. Bastit makes a comparison 
between the underground stem and the aerial leafy stem of mosses. 
The principal points noted are the following : — The underground stem 
has an epiderm provided with hairs, wliile the aerial stem is destitute 
of hairs. The underground stem has no hypoderm, while the aerial 
stem has one. The underground stem possesses three bundles and a 
very reduced cortex, with no pericyclic zone ; the aerial stem possesses 
numerous foliar bundles, a very much developed cortex, and a peri- 
cyclic zone. Finally, in the underground stem the pith is much 
developed and of a uniform structure, while in the aerial stem the pith 
is reduced, and is separable into two regions, the one central and the 
other peripheral. 
The following are the conclusions drawn by the author: — (1) That 
the stem of mosses is bounded by a true epiderm, characterized during 
the underground life by the production of absorbing hairs, and during 
the aerial life by the existence of a cuticle, and by intense cutiniza- 
tion of the walls. (2) The laminae of the scales and of’ the leaves are 
of epidermal origin. (3) The venation of the scales and the leaves is 
of internal origin. (4) The hypodermal zone of the aerial stem corre- 
sponds to the three peripheral angles of the rhizome. (5) The peri- 
cyclic zone of the aerial stem corresponds to the three sectors situated 
at the periphery of the pith of the rhizome. (6) In passing from the 
underground to the aerial portion, the diameter of the central cells of 
the pith and the lignification of their walls increase, while the periplieral 
elements undergo inverse modifications. 
Algae. 
Genera of Florideae.f — Prof. F. Schmitz gives a synopsis of the 
genera of Florideae hitherto described, which he classifies in four series, 
viz. Nemalioninae, Gigartininse, Rhodymeninee, and Cryptoneminse ; and 
the following families : — In the first, Lemaneaceae, Helminthocladiaceae, 
Chaetangiaceae, and Gelidiaceae ; in the 2nd, Acrotylaceae, Gigartinaceae, 
and Ehodophyllidaceae ; in the 3rd, Sphaerococcaceae, Rhodymeniaceae, 
Delesseriaceae, Bonnemaisoniaceae, Rhodomelaceae, and Ceramiaceae; in 
the 4th, Gloiosiphoniaceae, Grateloupiaceae, Dumontiaceae, Nemasto- 
maceae, Rhizophyllidaceae, Squamariaceae, and Corallinaceae. These are 
again in many cases divided into subfamilies, and the genera enumerated 
under each. Under each genus the name is also given of its typical 
species. 
Wrangelia, Naccaria, and Atractophora.J— Herr 0. E. Zerlang 
has carefully investigated the structure of the thallus, the reproductive 
organs, and the mode of fertilization, in Wrangelia penicillata, Naccaria 
Wigghii, and Atractophora hypnoides, and finds sufficient distinctive 
characters to keep these three genera of Floridem apart, although 
agreeing in their main features. 
In all three genera the fertilized oosphere itself, with or without 
previous fusion with adjoining cells, developes into the gonimoblast 
* Bull. Soc. Bot. France, xxxvi. (1889) pp. 295-303. 
t Flora, xlvii. (1889) pp. 434-50 (1 pi.). X T. c., pp. 372-407 (1 pi.). 
