646 
Notes . 
but this does not necessarily exclude their formation from the members of the 
enormously developed Equisetales of early Geological times. 
Slide R. 88 B. in the Manchester Museum (Fig. 58) shows a young Calamitean 
rootlet which has no papillae projecting into the cavities of the epidermal cells, but 
closely surrounding the rootlet, especially in the clefts, are small round bodies, appar- 
ently the cut ends of fungal hyphae. There seems to be some indication of the 
presence of hyphae in the walls themselves in one or two places, but this cannot be 
definitely asserted. As this is a very young rootlet, an early stage in the attack of 
the fungus may be represented here. 
Many of the older Calamitean roots show numerous projections from the 
thickened walls into the cavities of the epidermal cells and less frequently into cells 
belonging to internal layers. 
Fig. 59 represents an epidermal cell of one of these Calamitean roots (Q 285 
Cash Coll, in the Manchester Museum) containing a number of dark-coloured pro- 
jections from the thickened outer wall. 
These processes project further into 
the cavity of the cell than is usually 
the case; two of them are branched 
and two show swellings ; they vary in 
length and diameter. Two of the 
branches show a double outline, as if 
some substance had been deposited 
upon them, as was found to be the 
case with some of the fungal papillae 
in Galeola javanica described by Groom, 
and in Calypogeia trichomanis as de- 
scribed by Nemec. 
Fig. 60 represents a portion of a diarch rootlet of a fern which Dr. Scott has 
kindly identified as belonging to Rachiopteris corrugata , Will., one of the Botryopteri- 
deae (R 608 Hick Coll, in the Manchester Museum), in which the outer walls of 
some of the peripheral cells have become somewhat thickened and many of the cells 
have internal, dark, tapering processes from the walls, like those commonly found in 
the epidermoidal layer of Calamitean roots. Here, as in many Calamitean roots, 
these processes are not absolutely confined to the outer wall or even to the outer 
layer of cells, and the presence of a branching Fungus in the tissues of the rootlet 
makes it difficult to distinguish between these processes from the walls and fungal 
hyphae. The papillae vary in length and diameter, often expanding towards the base 
and sometimes appearing as mere knobs on the wall. Occasionally they branch, but 
on the whole they are much shorter than those shown in Fig. 59, so one would not 
expect much branching. Some of them show very distinctly a double outline — a 
dark core running through the centre of a light-coloured process. 
The hyphae in the internal tissues of the rootlet vary in diameter, some of the 
branches being very fine, others much stouter ; occasionally they appear to taper to 
a point, but this may be due to their taking a different direction of growth at these 
points, or to constrictions — such constrictions appear in various places in the mycelium. 
