100 REPORT OF THE BOTANIST OF THR- 
European species. Nothing will at present be said of the limita- 
tions or identity of species. The latter is a matter which must 
be determined largely by cross inoculations, together with mor- 
phological] studies. Inoculation experiments have been in prog- 
ress for two years, but they are not yet in shape to be fully 
reported; hence a presentation of the results will be deferred. 
Rhizoctonia is a form genus established to include certain 
sterile fungi occurring upon the roots of plants. The members 
of this genus, however, may be readily located by certain dis- 
tinguishing characters of the mycelium. In pure culture, more- 
over, a very characteristic form of growth is to be found. The ~ 
young hyphe growing in diseased tissue or in pure culture show 
a distinctive manner of branching; but as this character is in 
general the same for all, a description of the beet fungus will — 
suffice for this account. The young branches are inclined to the 
direction of growth of the parent branch at an angle more or less" 
acute. And the former are somewhat narrowed or constricted 
where united with the latter, as in Fig. 1. At a distance of a 
few microns from these places of union, a septum is invariably 
formed. The young hyphez are often strongly vacuolate; but 
later they usually become uniformly granular and more deeply 
colored. The branching also seems to have occurred more nearly 
at right angles to the main hypha, and the constriction at the 
place of union may not be so marked. (See Fig. 2.) On the beet 
root a short, tufted, or somewhat sporodochia-like growth of the 
mycelium may also occur. The hyphe of these tufts are brown, 
closely septate, constricted at the septa, and often branching 
in an irregular or dichotomous fashion, as in Fig. 3. Such hyphee 
may eventually break up into hyphal lengths of a single cell or 
several cells in extent. The individual parts then seem to func- 
tion as conidia, and germinate within a few hours when placed 
in suitable conditions. So far as observed, germination is al- 
ways by the protrusion of a tube through a septum. When sey- 
eral cells are connected, a germ tube from one cell may pass into 
and through its neighbor, as in Fig. 4, and thus peculiar appear- 
ances may result. Some of the cells of the hyphal chains seem 
