34 THIRTY-FOURTH ANNUAL REPORT OF THE 
that compose them are so closely united that it is not possible to dis- 
tinguish them easily. They appear to form asingle white stem crowned 
with a mass of spores. This form of the fungus is represented in fig. 
7. It was at one time thought to be, not merely a distinct species, but 
a distinct genus, and was named Coremium lencopus (the white 
stemmed Coremium) by Persoon. It was also called /'loccaria glauca 
by the celebrated Greville. It is now regarded simply asa variety of the 
crustaceous mold and takes the name variety Coremium. Sometimes 
the fertile threads go to the other extreme and become excessively loose 
and elongated in their mode of growth and send off a few fertile — 
branches as represented in fig. 8. 
Although so commonly found on decaying apples, this fungus is not 
limited to that habitat. It occurs also on pears and other fruits and 
various decaying vegetable substances. 
Besides the synonyms already given, Byssus scoparia, F). Dan., and 
Penicillium crustaceum, Fr., may be mentioned. 
Oidium fructigenum, Anz. and Schm. Fruit Oidium. (Plate 4, 
figs. 11-15.) Small, mealy-looking cushions or pustules sometimes oc- 
cur on the surface of apples. Single ones are scarcely larger than the 
head of an ordinary pin, but sometimes two or more occur so near. 
each other that they appear to run togetber and form larger and ir- 
regular masses. Their color is not very decided, but it is generally a 
dingy-white or grayish-yellow or a brownish-yellow, with a slight tinge 
of red. When very old they sometimes assume a blackish tint. They 
break out over a part or even over the whole surface of the apple, and 
are said to be more abundant in dry than in wet seasons. ‘The exter- 
nal visible part of the fungus consists of short more or less densely tufted 
threads, each one surmounted by a string of spores. These are some- 
what elliptical or egg-shaped, from which feature the generic name ap- 
pears to have been derived. As in most species whose spores are produced 
in necklace-shaped strings the spores readily separate from each other. 
In this fungus they are much Jarger than in the crustaceous mold al- 
ready noticed. The fungus attacks also pears, peaches, plums, ete., 
and is therefore appropriately called the ‘fruit Oidium.” With us it 
is especially common on plums. It does not always wait for the fruit 
to fall from the tree, but often attacks it while yet attached to the 
branches. Dried and withered plums yet dotted with the fungus cush- 
ions may sometimes be found still hanging on the trees in the spring 
of the year. It is even claimed by one writer that fruit is preserved 
by this fungus rather than destroyed. But my observations indicate 
that it does not preserve in an uninjured and pure condition. It first 
produces a kind of rot in the fruit, a ‘‘dry rot” perhaps it may be 
called. It is perhaps less pulpy and soft than the rot produced by some 
fungi, but the flesh becomes discolored and changed under the influ- 
ence of the mycelium. Some experiments illustrative of this were made 
by the writer with peaches. , 
On September 25th spores of the fungus were planted on a sound 
peach in three places; on the rind, on the scar that marks its place of 
attachment to the branch, and on the flesh which had been exposed by 
cutting away a minute portion of the rind. Those planted on the scar 
were at the same time moistened by a drop of water. 
On the next day there was a slight discoloration about the scar, A 
