96 
Cavers . — On the Structure and 
the densely granular fungus-protoplasm. The vesicles formed in autumn 
are usually terminal and isolated ; they have thick walls and evidently 
function as chlamydospores, from which new hyphae grow out in spring, 
when the growth of the thallus is resumed. The plants containing the 
Fungus are larger and show more vigorous growth than those free from 
hyphae, and there can be little doubt that we have here a definite sym- 
biosis, the Fungus forming a mycorhiza by means of which the life of the 
Fegatella - plant becomes to a certain extent saprophytic at the expense 
of the humus on which it is growing. 
Golenkin (1902) has recently studied the mycorhiza of various Hepa- 
ticae, including Fegatella , and states that the infected cells never contain 
starch or chloroplasts. This is not quite true in the case of Fegatella , 
according to the present writer’s observations, for here the fungal hyphae 
may be seen traversing cells which contain starch-grains, and in a few cases 
the hyphae were seen to have also invaded the chlorophyll-bearing cells 
that form the floor of each air-chamber. Golenkin suggests that the func- 
tion of the mycorhiza in the Marchantiaceae is that of storing water and 
enabling the plant to resist drought, but this explanation will hardly apply 
to a thoroughly hygrophilous form like Fegatella , which possesses in its 
mucilage-sacs a special tissue that may very reasonably be considered as 
fulfilling the requirements of water-storage in an exceptionally complete 
manner. 
Since the observations of Beauverie and of Golenkin are in many 
respects lacking in detail, and do not form a sufficient basis for conclusions 
as to the biological importance of the mycorhiza in the Marchantiaceae, 
the writer has made a series of cultures, the results of which, though in 
some respects incomplete, may be here briefly given. 
On sowing ripe spores in heat-sterilized soil it was found that a 
relatively small number of young plants was obtained, and that these 
were always poorly developed, the thallus being long and narrow; the 
ventral scales were small and remained green throughout, and only smooth- 
walled rhizoids were formed. In no case were any fungal hyphae to be 
found in the tissues. 
For comparison, an approximately equal number of spores (the entire 
contents of a ripe capsule) was sown in ordinary garden soil, under similar 
conditions as to light and moisture. A much larger proportion of young 
plants was obtained, and in many cases these plants showed broad thallus- 
lobes with well-developed air-chambers, scales with violet-coloured appen- 
dages, and tuberculate rhizoids. In the smaller plants the thallus was 
free from fungal hyphae, but these were found abundantly in the larger 
and more vigorous plants. 
A third lot of spores was sown in rich humus (peaty soil). The young 
plants were more numerous and showed more vigorous growth than in the 
