32 
F. Cavers — 
which forms the substratum, so that the moss-plant assumes a more 
or less saprophytic mode of life. A precisely similar adaptation 
has been found by the writer to exist in certain Hepaticae. Thus in 
Lophocolea bidentata , which frequently occurs on decaying wood, 
the gametophyte appears to be entirely free from fungal hyphae, 
but the rhizoids, which are borne in tufts at the bases of the 
amphigastria, penetrate the substratum, their ends becoming 
profusely branched, like the haustoria of many Fungi. In many 
exotic Lejeuneae and Frullaniae which grow on the stems and 
leaves of living trees, the rhizoids show a similar haustorium-like 
penetration of the substratum, and it is highly probable that they 
serve not only for attachment but also for the absorption of organic 
food-materials. In several specimens of these epiphytic liverworts 
(kindly presented to the writer by Mr. M. B. Slater, of Malton), 
the plants were found growing over lichens, into which the rhizoids 
had become inserted, undergoing repeated branching and becoming 
interwoven with the lichen-tissue in a complicated manner. More¬ 
over, the parts of the liverwort which had thus become intimately 
connected with the lichen showed a more luxuriant growth than 
those that came into direct contact with the stems or leaves on 
which the liverwort and lichen were together growing as epiphytes; 
the leaves were larger, and in the case of Frullanias the increase in 
size of the water-pitchers (“lobules” or “auricles”) was frequently 
very marked. 
Fungal hyphae have been observed in the tissues of the game¬ 
tophyte in a considerable number of Hepaticae, both thalloid and 
foliose, and in some cases there can be no doubt that the association 
of the fungus with the liverwort is of a symbiotic nature. 
In 1879 Kny, 1 in describing the peculiar regeneration-process 
which is frequently observed in the rhizoids of Lunularia and 
MarcJiantia , namely, the development of secondary or even tertiary 
rhizoids within the primary rhizoids, states that the latter are some¬ 
times traversed by branched but sterile fungal hyphae. The writer 
has found that when these liverworts are growing in ordinary soil, 
the fungal hyphae may penetrate the rhizoids, growing upwards as 
delicate filaments which show cross-walls at rather long intervals 
and occasionally become branched, but not reaching the compact 
tissue of the thallus. On examining plants that had been growing 
on rich humus, however, it was found that not only did the plain 
1 Kny uud Bottger, Ueber eigenthumliche Durchwachsuugen 
an den Wnrzelhaaren zweier Marckantiaceen. Verliaudl. 
d. botan. Vereins d. Prov. Brandenburg, 1879, p. 2 of 
separate. 
