56 REPORT OF THD BOTANIST OF THE 
observed for the first time upon the carnation rust. In a green- 
house at Flatbush, Long Island, it has been found on the variety 
_ Gen. Maceo; and in each of three different greenhouses at Geneva 
on several different varieties: While not naturally very effective 
as a check, by the use of artificial cultures or inoculations some 
benefit may be derived from its presence, 
THE PARASITE. 
(Darluca filwm (Biv.) Cast.). 
This fungus is related to the Septorias and Phomas familiar to 
florists through the diseases they produce. In some way this 
fungus has become adapted to living upon the tissues of other 
fungi instead of deriving its nourishment solely from the host 
plant. 
The presence of Durluca is best determined with the micro- 
scope. But in cases where the rust is badly infested, the dwarfed 
and evidently crippled development of the rust pustules indicates 
that something is wrong. At times there are dead areas, in which 
are scattered a number of very fine black specks; these are the 
pycnidia of the Darluca. In other cases the infested area is 
nearly black, and the pycnidia are abundant. A third type of 
infestation is visible only with the aid of the microscope; in this 
the pycnidia are scattered among the spores in the infested pus- 
tules, which otherwise appear normal. In any case the presence 
of the Darluca, as of the rust, is shown externally only when it 
reaches maturity aud produces spores. “ 
The spores of Darluca are two-celled and colorless. They are 
developed within pycnidia or flask-shaped fruit-bodies, which 
may be nearly spherical, or much elongated. When a ripe pycni- 
dium is moistened, the spores are expelled in a thiek rope, which 
holds together by the gelatinous covering of the cell walls of the 
spores. | | 
The pycnidia are formed from a cluster of interwoven vertical 
branches of hyphe. As the mass thus begun develops, a cavity 
is formed at the center, which enlarges until only a thin mem- 
brane is left as the pycnidial wall. From the interior of this 
