133 
1917-18.] Phycomycetous Fungi. 
hyphse are found within the cells of the host, the fungus having been 
intra- rather than inter-cellular in its mode of growth. 
Mycelium. 
In the majority of cells the hyphse are preserved in fragments only 
(Plate, fig. 1), but, in some cases, single threads can be followed in their 
passage through several cells (Plate, fig. 2). The hyphse vary in thickness 
from 2/x to 4/x. Individual threads do not show any marked variations in 
thickness. Some of them are presented “ end on ” to the eye : such exhibit 
a tubular structure, and in them also the delicate membrane can be seen 
to advantage. The threads branch monopodially, the branches, sparingly 
formed, being of the same thickness as the parent hyphse. Renault (8) 
ascribes a dichotomous branching to this fungus, but in his figures 
(Meschinelli, tab. v, fig. 14 ; tab. vi, fig. 1) monopodial branching is indicated. 
A few of the hyphse with vesicles in attachment, found in the reticulate 
tracheides of a young stem of Lyginodendron Oldhamium, are shown in 
text-fig. 1. Under high magnification inside the threads are seen small, 
ill-defined, irregular lighter areas, set in a groundwork of a deeper brown 
