ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
653 
Botrycliium virginianum , among the moro important of which are the 
following: — The gametophyte is entirely subterranean, without chloro- 
phyll, and is probably symbiotic. The whole surface is furnished with 
rhizoids which are mostly multicellular. The reproductive organs are 
found exclusively on the upper surface. It possesses a well-marked 
apical meristem. The endophytic fungus appears to be intermediate 
between the genera Pythium and Completoria. The neck of the archegone 
consists of seven or eight tiers of cells; the neck-canal-cell has two 
nuclei. The root, stem, and cotyledon grow by the segmentation of a 
single apical cell. A single instance of polyembryony was detected ; 
also an indication of apogamy. 
Mucilage-Canals of the Marattiaceae.* — M. L. Lutz states that in 
the leaves of the Marattiaceae ( Marattia fraxinea, Angiopteris evecta ) 
there are two kinds of mucilage-canals ; the one true intercellular spaces 
formed schizogenously ; the others originating in the first place from 
rows of cells rich in tannin and poor in mucilage, which become trans- 
formed, by the gelification of their transverse septa, into mucilage-cells, 
without any small bordering cells, as is the case with those of the first 
kind ; these latter have, therefore, a lysigenous origin. 
Muscineee. 
Xndusiella, a new Genus of Musci.f — From Central Asia, Herr Y. F. 
Brotherus describes a new genus of Mosses, which he thus characterises : 
Genus curiosissimum Tortulacearum, juxta Aloinam ponendum, sed foliis 
elamellosis, seta perbrevi, theca ovali, peristomio erecto et calyptra 
magna campanulata, longe diversum. 
Modifications of the Thalius of Marchantia and Lunularia.J— 
M. J. Beauverie has made a series of experiments on the alterations in 
the structure and mode of growth of these Hepatic® produced by ab- 
normal conditions of illumination, exposing them to a feeble, but 
constant and uniform light. In place of the ordinary flat creeping 
thalius there appeared a number of narrow vertical green plates, the 
original flat tballus exhibiting signs of disorganisation. The author 
regards the flat plagiotropic growth of the thalius of these plants under 
ordinary conditions as the result of an equilibrium resulting from the 
action of a negative geotropism and a negative heliotropism ; when 
the action of light is removed, the negative geotropism alone comes into 
play. The structure of the modified thalius undergoes a great change ; 
the air-chambers and the pseudo-stomates almost entirely disappear, 
and the distribution of the chlorophyll becomes completely changed, the 
difference between the two surfaces being greatly reduced. It would 
appear, therefore, that the dorsiventrality of the ordinary thalius of the 
Hepatic® may almost entirely disappear under altered conditions, but it 
always remains latent ; the lower surface can never be made to produce 
stomates, nor the upper surface rhizoids and amphigasters. 
* Journ. de Bot. (Morot), xii. (1898) pp. 133-5 (1 pi.). Cf. this Journal, 1895, 
p. 659. t Bot. Centralbl., lxxv. (1898) pp. 321-2. 
X Ann. Soc. Linn. Lyon, xliv v (1898) pp. 57-69 (9 figs.). 
