484 Ridler.—Further Observations on the Fungus 
the liverwort can be recognized in sections of fresh material examined with 
a low power magnification (x 100), but individual hyphae cannot be so 
distinguished. Under a higher magnification (x 440) numerous relatively 
large hyphae are visible. These branch profusely, passing from cell to cell 
by piercing the cell-walls. Except at the points of penetration no injuries 
to the cell-walls, owing to the passage of the hyphae, have been detected, 
nor have any traces of the presence of an enzyme causing the destruction of 
the cell-wall been observed. Penetration of the cell-walls seems, therefore 
Fig. 2. Cells of Pellia epiphylla containing 
‘ arbuscules’. h ., hyphae ; 11., nucleus ; ar., ar- 
buscules. x 290. 
h 
-sp 
Fig. 3. Cells oi Pellia epiphylla containing 
‘sporangioles’. h hyphae ; sp ., sporangioles. 
x 290. 
to be effected mechanically. The hyphae are distinctly swollen where their 
growth is arrested by cell-walls, and are constricted for their passage 
through them (Fig. 1). 
Numerous very fine and profusely branching threads are produced 
from some of the hyphae, and form a network which completely fills some 
of the cells (Fig. 2). These threads, which can be made more conspicuous 
by staining with picro-nigrosine, probably correspond to the ‘ arbuscules ’ 
described by Noel Bernard ( 1911 ) in Solarium Dulcamara , and by J. 
Magrou ( 1921 ) in Solannm tuberosum , Orobus tuberosus, and Mercurialis 
perennis . These ‘ arbuscules ’ degenerate later into irregular masses termed 
by Bernard ‘sporangioles’ (Fig. 3). These masses are insoluble in water, 
alcohol, benzol, chloroform, and other similar solvents, also in the 
