258 Researches into the Nature of the Potato-Fmigus. 
I have examined, presents the following characters : On a sheet 
of mica is an entirely colourless section of a potato, dried up, 
the walls of the cells mostly quite empty, but some still retain- 
ing starch grains. Many slender threads of fungus, in which 
for the most part no distinct structure can be any longer re- 
cognised, pass through the preparation, and there are besides 
numerous globular bodies of two kinds, abounding in protoplasm, 
strewn over it. The one kind cannot with certainty be distin- 
guished from those star-shaped bodies I have described, in which 
the prickly envelope is entirely filled by the smooth globule. 
They present no organic connection with the other forms of 
fungus, but lie free among them. Montagne draws them as 
isolated organisms, both in the sketch published by Berkeley, 
and in another which he sent me in 1863. In the second 
place, the preparation exhibits globular or oval cells with 
very dense protoplasm, which are somewhat larger in dia- 
meter than the prickly ones, and are always distinctly sup- 
ported on septate fungus threads, mostly intercalated, seldom 
apparently terminal. The wall of these cells is in many 
cases moderately thick ; in others it appears to be very thick, 
shining and gelatinous. The granular protoplasm is surrounded,. 
at least in the moistened 
Fig. 8. specimens, with a broad, 
shining, colourless border, 
which I can regard only as 
such a membrane (see Fig. 8). 
Montagne and Berkeley have 
explained the globular cells 
of both kinds as exhibiting 
progressive steps in their de- 
velopment, the smooth ones, 
being the younger. For this 
no reason is given, nor have 
I found any in the renewed 
examination of the specimens. 
And one can scarcely con- 
ceive, from the known phe- 
nomena of development, how 
the smooth thick-walled cells 
could become the smaller star- 
shaped ones. But the fact is, 
that we have here two forms of 
fungus, which are locally associated, and which were more easily 
confused with each other thirty years ago than appears credible 
to us now. The specific name hydnosjm'us shows that Montagne 
had drawn it chiefly from the prickly form. The other form 
Smooth globules on thin mycelium threads, from 
Montauue's original specimen of Artotrogiis. 
i Magn. 375 diam. 
