1888.] Dr A. B. Griffiths on Fungoid Disease. 405 
and that this particular species infests the roots of the cucumber 
{Gucumis). Having made a complete study of the life-history of 
this fungoid growth, I have now the honour of laying my observa- 
tions before the Eoyal Society of Edinburgh. 
Fig. 1 represents the roots and rootlets of Cucumis sativa con- 
taining these abnormal outgrowths. These structures are small at 
first, hut grow very rapidly, producing nodules sometimes as large as 
a good-sized marble. They appear to be produced pretty plentifully 
on those parts of the root where there are an abundance of rootlets 
and root-hairs. This, to my mind, appears to be accounted for by 
the fact that the fungus (see analyses) requires organic nitrogenous 
compounds in large quantities ; and these are most likely obtained 
in the rootlets, after the direct absorption of organic and inorganic 
nitrogen from the soil. 
In fig. 2 is represented a diagrammatic transverse section of a 
root with nodule. In very thin sections, and under high power, the 
nodules are seen to be filled with hyphse and spores. By using 
Schultze’s solution the mass of spores in the section turns a bright 
yellow colour and the cellulose walls of the parenchymatous cells 
(containing the spores) become blue. The spores are beautifully 
stained by a solution of hmmatoxylin. With iodine the spores 
become light brown in colour. The spores of this fungus are more 
or less V-shaped, and are formed by division of the protoplasmic 
contents of the hyphal filaments which ramify in the root-tissues of 
the host-plant. The hyphae are not divided by transverse septa. 
The cellulose walls of these filaments are stained a yellowish-brown 
by using Schultze’s solution, showing their true fungoid nature. 
As fig. 4 shows, the hyphae (which are many times thicker than the 
cell- walls of the adjacent tissues) pass, cell by cell, through the 
cortex of the rootlet, also sometimes across the intercellular spaces. 
Branching of the hyphae is well marked in the tissues of the 
nodules, and sometimes they send out lateral branches which end 
abruptly in the cells. These secondary or lateral hyphae have a 
number of tufted haustorium-like bodies (fig. 5). The hyphae in the 
cells filled with spores are generally short and much branched, and 
they pass through the cellulose walls of the cells. In their passage 
through the cell-walls I have not observed the peculiar widening 
of ^the hyphae on either side of the ‘‘ walls,” as was seen by 
