South African Perispoonaceae. 
123 
morphologically similar to I. natalensis, differing only in minor points in the 
form of the hyphopodia and spores. It is interesting to find, therefore, that 
the haustoria are of a different type. Those of I. imiggarii have a fine, blue- 
staining penetrating filament, and a small uninucleate vesicle about 6 ft diam. 
in the epidermal cell. The specimen examined was on Clifortia strohilifera, 
which has not a very thick cuticle, but it is wavy in outline. The difference 
in the haustoria cannot be accounted for by the character of the host plant, 
for both species occur on plants with quite a mesophytic type of leaf. 
Fig. 3. — 31. Podocarpi on leaf of Podocarpus falcata (comp. oc. No. 8). 
Some of the most interesting results were obtained in connection with 
two fungi parasitic on Podocarjms spp., which further emphasise the fact 
that the form of the haustorium is a specific character, and is not dependent 
to any great extent on the structure of the host. 
Irene podocarpi Doidge is found on Podocarpus Thnnhergii, P. falcata 
and P. elongata, and specimens on the two last-named hosts were examined. 
This fungus has the most usual form of haustorium, consisting of a thin- 
walled penetrating filament with a small vesicle in the epidermal cell (Fig. 3). 
It occurs mostly on the under side of the leaf where the cuticle is not very 
thick. 
