34^ 
MUS CI NE JE. 
CLASS V. 
HEPATIC^i. 
(i) The Sexual Generation (Oophore) is developed, in some genera, directly 
from the germinating spore, its first divisions resulting in the formation of a cellular 
lamina or a mass of tissue which fixes itself by root-hairs and produces the thallus 
by growth at its apex, as in A?tthoceros and Pellia. In other cases the body which 
results from the divisions of the spore first forms a narrow ribbon-like lamina of 
cells, the apical cell of which becomes subsequently the apical cell of a stem, and 
its segments form leaves, as in Jungerniannia bicuspidata (according to Hofmeister). 
Or again, the bud of a leafy stem springs immediately from the spore {Frullatiia 
dilatatd). In other cases, on the other hand, a protonema is formed ; the endospore 
which grows out into the form of a tube produces a short articulated filament on 
which the rudiments of the thallus are formed as lateral shoots, in a manner similar 
to the leaf-buds of Mosses on the protonema {e.g. Amur a palmata., Marchaniia). 
In Radula the spore produces first of all a flat plate of cells, from which the first 
bud of the leafy stem springs laterally (Hofmeister), a process which finds its ana- 
logue among Mosses. 
The vegetative body of Hepaticse is always formed in a distinctly bilateral 
manner; its free side, turned towards the light, is differently organised from that 
which faces and often clings closely to the substratum and is not exposed to light. 
In the greater number of families and genera the vegetative body is a broad, 
flat or curled plate of tissue, varying in length from a few millimetres to several 
centimetres ; and is either a true thallus without any formation of leaves, as in 
Anthoceros, Meizgeria, and Aneura, or lamelliform outgrowths arise on the under 
or shady side, which at the same time produces root-hairs ; and these outgrowths 
may be looked on as leaves. For the sake of having a common expression for these 
forms extremely similar in habit, they may be comprised under the term Thalloid'^, 
^ Mirbel, Ueber Marchantia, in the Mem. de I'Acad. des Sei. de I'lnst. de France, vol. XIII, 
1835.— G. W. Bischoff, in Nova Acta Acad. Leopold. Carol. 1835, vol. XVII. pt. 2.— C. M. Gottsche, 
ibid., vol. XX. pt, i. — Gottsche, Lindenberg u. Esenbeck, Synopsis Hepaticarum, Nürnberg, 1844. — 
Hofmeister, Vergleich Untersuchungen, 1851. — [On the Germination, Development, and Fructifica- 
tion of the Higher Cryptogamia : Ray Society, 1862,] — Kny, Entwickelung der laubigen Lebermoose ; 
Jahrb. für wiss. Bot. vol. IV. p. 66, and Entwickelung der Riccien, ibid., vol. V. p. 359. — Thuret, in 
Annal. des Sei. Nat. 1 851, vol. XVI (Antheridia).— Strasburger, Geschlechtsorgane u. Befruchtung bei 
Marchantia; Jahrb. für wiss. Bot. vol. VII. p. 409: [also Befruchtung und Zelltheilung, 1878]. 
— Leitgeb, Wachsthumsgeschichte der Radula complanata ; Sitzungsber. der Wiener Acad. 1871, 
vol. LXIII. — Ibid., Bot. Zeitg. 1871, no, 34, and 1872, no. 3. — A portion of what is said about the 
apical growth of Jungermannieae is derived from communications by letter from Leitgeb. — Janc- 
zewski. Bot, Zeitg, 1872. — [Leitgeb, Unters, ueb. Lebermoose, 1874-78. Goebel, Zur vergl. Anat. 
der Marchantieen, Arb. d. bot. Inst, in Würzburg, II. 3, 1880.] 
^ [The term 'thalloid' is here, as on p. 342, preferred to the one in more general use, 
' frondose.'] 
