170 The Means of Distribution of Hepaticce. 
may reasonably infer that our present representatives are of ancient 
origin and have come down to us from the Miocene epoch. 
The distribution of Marchantia polymorpha and of Lunularia 
cruciata is to be explained by the asexual production of gemmae and 
the ease with which these bodies are transmitted from place to 
place by mechanical agencies. To all intents and purposes they 
function as seeds, and to their agency is to be attributed the 
reappearance of plants in spring at those stations, from which they 
temporarily disappeared during the winter. This conclusion was 
forced upon the writer some three years ago after keeping obser¬ 
vation upon the growth at various stations, which led him to make 
experiments. A number of gemmae were removed in the late 
autumn from the parent structure and planted in brick-work crevices 
at the bottom of a damp wall in the writer’s garden, with the result 
that in the following spring he had quite a crop of Lunularia. 
These bodies, coated as they are with adhesive mucilage, not only 
become readily attached to the coats of animals and are conveyed 
from place to place, but retain their vitality through the winter. 
This view will account for the presence of Lunularia in those 
situations more or less frequented by rats, as in the neighbourhood 
of gullies, sewers, &c. as well as in the more open situations to 
which the gemmae may have been conveyed attached to the feet of 
birds. 
The multiplication of Lunularia cruciata by gemmae during the 
early spring and summer is extremely rapid. Often two or even 
three cupules may be seen on one and the same thallus, and since 
the horns of the semi-lunar cupules are directed towards the apices 
of the plants, the gemmae when mature, are guided outwards and 
downwards to new unoccupied soil. This circumstance accounts 
for the thickly matted clumps occurring so rapidly in the neighbour¬ 
hood of isolated plants during the early summer months, whilst the 
migration of birds will account for its distributian in widely 
separated areas. 
Fegatella conica, belonging to the Marchantiaceae, and Pellia 
epiphylla, belonging to the thalloid Jungemanniaceae, surpass in 
robustness the genera hitherto dealt with and seem to be quite at 
home in their British stations. They both are able to complete 
their life-cycles annually and are widely distributed. Fegatella 
conica is met with in great profusion in the counties of Kent, Sussex 
and Surrey, occupying the banks of the upper courses of the 
Medway and Rother and the many streams and brooklets feeding 
