17 
The disease, however, was collected on both sycamores and oaks 
in certain localities on Long Island. This fact suggests the close 
relation between the trees in the city parks and those of outlying 
districts on the Island, and shows the necessity of including in 
this study a much wider area than the city limits, especially in 
connection with plans for remedial measures and control. 
The catalpa trees, particularly the large ones in Prospect Park, 
were very severely attacked by the catalpa leaf spot, Phyllosticta 
catalpae Ell. & Mart. Practically every leaf on the trees, about 
the middle of July, had a dozen or more distinctly infected areas. 
In some cases, the infected areas of the leaf were more extensive 
than the sound tissues. Such badly diseased leaves fell from the 
tree. Fora short period, near the middle of July, every day or so 
the ground would be fairly covered with leaves that had fallen 
off. Again, however, due to the fact that the catalpa continues 
to put out new leaves during the growing season, the disease 
seemed to have practically disappeared by the first of September. 
The rhododendrons were badly infected with a fungus which 
has not been certainly identified. The tips and margins of the 
leaves turned brown and fell from the bushes prematurely. A 
large proportion of the leaves of the plants were infected, result- 
ing in a conspicuous defoliation of the shrubs. 
The roses in the rose garden of the Park were infected with 
the common rose leaf spot, Actinonema Rosae (Lib.) Fr. Some 
of the varieties were much more severely attacked than others. 
In general, however, the attack was not so severe as to materially 
affect the appearance of the plants. 
In the latter part of August, a leaf disease on some of the mag- 
nolias became conspicuous. Apparently the cause of the disease 
is Phyllosticta cooket Sacc. 
Early in September the powdery mildew, Microsphaera alumi 
(Wallr.) Salm., of the lilac was becoming very conspicuous. 
The fungus was in the conidial stage and was rapidly spreading 
over the leaves of the shrubs. Powdery mildews usually appear 
late in the season and additional forms on other hosts would cer- 
tainly have been found if it had been possible to collect them 
later in September. 
Relatively few fruiting bodies of the higher fungi, which cause 
ee al 
