334 
The Ohio Naturalist. 
[Vol.XI, No. 6, 
of which we have about a hundred species, now known, in North 
America, and well worth being studied, are of much smaller size, 
the mussels being 1.5 to 20 mill, long when mature; their hinges 
are more complete; the mantle is less open and the siphons are 
closed, and tubes; the four branchiae are differently arranged; the 
young are developed in a special, brood pouch on the inside of 
the inner branchiae on each side; the young, when mature, are 
much larger than the glochidia of the Unionidae and fully 
developed. 
New Philadelphia, Ohio. 
THE OCCURRENCE OF APPLE BLOTCH IN OHIO. 
W. O. Gloyer. 
In the early part of September of this year there came an 
inquiry to the Department of Botany of the Ohio Agricultural 
Experiment Station from an orchard grower of Sharon, Noble 
County, seeking advice in regard to the blotched appearance of 
some of the apples found in his orchard. Examination of the 
specimens, by Mr. Arzberger, of this department, revealed the 
presence of the Apple Blotch, Phyllosticta solitaria, E. & E. This 
disease was reported by Scott* in 1909 as being quite prevalent 
in our southern states, causing a great deal of damage in the 
orchards infected. Investigations in the orchards in the vicinity 
of Wooster showed its presence on a local variety of apple known 
as ‘‘Butter Apple.” All the trees of this variety in the orchard 
were infected to about sixty per cent of their crop, while other 
trees under similar conditions were immune. 
Inquiries and inspection of the orchards in our southern 
counties revealed the fact that the apple blotch was quite prev- 
alent in sprayed as well as unsprayed orchards. Usually one 
variety in an orchard suffers to a great degree while the remainder 
of the orchard is not infected. In one orchard, for instance, 
twenty barrels of Pippins were infected to about ninety per cent, 
while the other varieties were immune. The investigations in 
Lawrence, Gallia and Jackson Counties showed that Phyllosticta 
solitaria occurred frequently on Smith’s Cider, Baldwin, Ben 
Davis, Stark, Pippin, and Rome Beauty. Often, as was the case 
with the Pippin, the entire crop was ruined by this disease. The 
disease has also been found in Wayne, Noble, and Athens Counties. 
The fungus is not only found on the fruit, but its presence is 
also noted on the leaves and twigs; nevertheless, the disease is not 
suspected in the orchard unless the disease has made itself evident 
on the apples. The dark-brown stellar spots (Figs. 1 and 3), 
* U. S. Bull. 144, Bureau of Plant Industry. 
