Asexual Reproduction in Hepaticae. 127 
In a tropical epiphytic species of Metzgeria, described and 
figured by Ruge, 1 the thallus bears erect cylindrical outgrowths 
arising from the dorsal surface of the mid rib. The superficial 
cells of these erect shoots grow out into discoid gemmae, oval in 
outline, each gemma being attached by a single stalk-cell and readily 
becoming detached. In Metzgeria conjugata, erect gemmiferou, 
shoots were observed by Goebel, 2 who states that the gemmae arise 
in the same manner as those of Aneura , but before being set free 
each gemma has by continued growth and cell-division assumed the 
form of a concave cell-surface, the “two-sided” apical of the shoot 
being recognisable on the margin of the discoid gemma. Lett 3 
states that in M. furcata , var. aeruginosa (Hook.), “the fronds 
mostly bear gemmae in abundance on their ends, and then the 
branches have their margins so much curved back as to appear 
cylindrical, and not wider than the nerve.” 
Fam. 3. Leptotheceae. In Pallavicinia and Symphyogyna , 
which are included in this small family, and also in Hynieno pity ton, 
which belongs to the Metzgerioideae, asexual propagation is effected 
by the formation of ventral branches which arise from the sides of 
the mid-rib and ultimately become separated from the parent shoot. 
In these forms, the cylindrical mid-rib of the thallus is traversed by 
one or more axial strands, the cells of which are long, narrow, pointed 
at the ends, and bear spirally arranged slit-like pits on their walls. 
When a branch is laid down, its apical cell for some time produces 
only broad thin-walled cells, so that the later-formed axial strand of 
the branch is not continuous with that of the parent shoot, from 
which the branch readily becomes detached. 
Fam. 4. Codonioideae. Pellia frequently bears adventive 
shoots, which arise from the superficial cells on the dorsal surface 
or the margins of the thallus and ultimately become detached. 
Similar adventive shoots are sometimes observed on the ventral 
surface of the stem in Blasia pusilla and in Petalophyllum Ralfsii , 4 
Gemmae occur in three genera belonging here, namely, Treubia, 
Blasia , and Cavicularia. In Treubia insignis, a large foliose form 
1 Ruge, G., Beitrage zur Keuntuiss der Vegetationsorgaue der 
Lebermoose. Flora, 1893, Heft. 4, p. 3o of reprint. 
2 Goebel, K-, Organographie der Pflauzen, p. 275. 
3 I.ett, H. W., A list, with descriptive notes, of all the species 
of Hepatics hitherto found in the British Islands, 1902, 
p. 21. 
4 For material of this interesting and rare form, the writer is 
indebted to the kindness of Mr. W. H. Pearson. 
