a Fungus causing a Disease of the Sugar-cane. 523 
just within the mother-cell ; this septum, however, is confined 
to the protoplasmic contents and not connected with the wall 
of the mother-cell. The segmented apical portion of proto- 
plasm continues to grow out of the mother-cell, accompanied 
by a simultaneous constriction at the septum and rounding 
off of the apical portion of protoplasm, which eventually 
projects beyond the sheathing open apex of the mother-cell 
as a spherical conidium, attached by a constricted neck to 
the protoplasm included within the mother-cell. In one in- 
stance the formation of a conidium, from the moment of 
deliquescence of the apex of the wall of the mother-cell to 
the complete formation of the exserted globose conidium, 
occupied forty-six minutes. When quite young, the proto- 
plasm of the conidium presents the appearance of a coarse, 
irregular network, due to numerous vacuoles ; these however 
soon disappear, and three or four smaller persistent vacuoles 
take their place- When developed under normal conditions 
in the cane, two permanent vacuoles are usually present, one 
at each pole. Chlor-iodide of zinc demonstrated the presence 
of a delicate cell-wall of pure cellulose on the exposed part 
of the developing conidium, the colour indicating this dying 
away at the point still contained within the mother-cell ; 
When first formed the wall of the conidium is colourless ; in 
about twelve hours it becomes tinged with clear olive-green ; 
in twenty-four hours it becomes sooty-brown, and finally 
opaque blackish-brown. Succeeding conidia are formed in 
a manner similar to the first, but differ in being elliptical or 
barrel-shaped with truncate ends, whereas the first formed 
terminal conidium is always spherical, measuring 24-26 /x 
in diameter, the barrel-shaped ones averaging i8-2oxi2/x. 
In cultures fifty conidia are often present in a chain, and in 
one instance sixty-seven were counted (Fig. 8). When de- 
veloped in a cane, the conidia are smaller, the terminal one 
measuring 20 /x diam., the others 16-19x10 /x, and as a rule 
not more than twenty conidia are present in the chain. 
From the description given, it will be observed that the 
macroconidia are formed in a manner unusual amongst fungi, 
