Asexual Reproduction in Hepaticae. 123 
Fam. 3. Targionioideae. Targionia is characterised by the 
constant production of ventral shoots from the sides of the mid-rib. 
The m.iin axis seldom shows apical branching, its growth in length 
being usually arrested by the formation of the female receptacle. 
The ventral shoots become detached at the base and form new 
plants. 
Fam. 4. Marchantioideae . In many of the forms belonging here, 
especially in the section “ Operculatae,” e.g., Reboulia , Asterella , 
apical branching is largely replaced by the formation of ventral shoots 
which arise near the apex of the thallus or from the sides of the 
mid-rib farther back. In two Californian species of Asterella, 1 viz., 
A. Bolanderi , A. violacea, both the antheridia and the archegonia are 
borne on short latero-ventral branches, and doubtless in these, as 
in other species, sterile branches arising in this way may become 
detached and produce new plants. In Fegatella supradecomposita , 2 
a Japanese form, the growing-point of each of the thallus lobes 
frequently gives rise to a circular discoid outgrowth, which bears 
ventral scales and obviously represents a modified branch. Instead 
of simply growing out to form a continuation of the main shoot, 
like the resting branches formed in autumn in F. conica , each of 
these buds or branches in F. supradecomposita becomes detached at 
the base and gives rise to an independent plant. In F. conica itself, 
as was first shown by Karsten, 3 tubers are often formed on the 
ventral surface of the mid-rib, especially in old plants which have 
become covered over by the younger shoots. Here and there the 
cells immediately below the surface grow and divide actively, giving 
rise to a mass of tissue which later breaks through the super¬ 
ficial layer and projects as a small spherical ovoid outgrowth, 
attached by a short narrow stalk. This tuber bears rhizoids, its 
cells contain starch-grains, and it ultimately drops off and grows out 
to form a new plant. The tubers of Fegatella , which grows chiefly 
beside streams, are not adapted to withstand drought, as are those 
of the xerophytic Riccia- species above mentioned; they perish if 
kept dry for a few days. 
Adventitious shoots have in rare cases been observed to arise 
from the specialised female branches (archegoniophores) of Mar - 
1 Howe, 3\I.A., The Hepaticae and Anthocerotes of California. 
Mem. Torrey, Bot. Club, Vol. 7, 1899. 
* Lindberg, S.O., Sandea et Myriorrhynchus nova Hepaticarum 
genera. Acta Soc. pro Fauna et FloraFeunica, Vol. 2, 1884, 
nr. 5 ; Goebel, Orgauographie der Pflanzen, p. 274, fig. 174. 
* Karsten, G., Beitrage zur Kenntuiss von Fegatella conica. 
Botan. Zeitung. 1887, p. 650. 
