22 
Gloeosporium, Marssonina, Phyllosticta, Rhytisma, Septoria, 
Taphrina, ete. Although Phyllosticta labruscae Thuem. on the 
ivy, P. mimma (B. & C.) E. & E. on the red maple, P. phomi- 
fornus Sacc. on the oak, Rhytisma acerinum (Pers.) Fr. on the 
eae a at betularum IX. & M. on the birch, G. cana- 
e fe. & E. on the oak, and other fungi that might be men- 
rie were very common in different localities, none were ob- 
served in the Park or the Garden. This may be due in part to 
the relative absence of young hosts and to the generally unfavor- 
able environmental conditions. The air of the park certainly 
contains less moisture than the dense woods along streams. Fur- 
ther the air of cities is known to contain various noxious gases 
from chimneys, manufacturing plants, and other sources. 
The conditions found in the Park and Garden are not excep- 
tional, Similar conditions are doubtless to be found in any large 
city park. The problem of combatting the various diseases is a 
very difficult one, involving the use of all available means. The 
trees of a park are always in danger of infection from diseases in 
the adjacent region, and constant care must be exercised to guard 
against them. 
One of the most interesting fungi collected was the rust of 
Sempervivum, Endophyllum sempervivi (Alb. & Schw.) de 
Bary. This rust was found on some Sempervivum plants in the 
Garden. Since this common European rust had not been. previ- 
ously reported for this country, an attempt was made to deter- 
mine the source and time of its introduction. The nursery from 
which the Garden secured the Sempervivum plants a year earlier 
was visited, and a number of additional specimens of the rust 
were secured. It appears that the nursery had imported Semper- 
vivum plants from Holland about twelve or fifteen years ago; 
since that time the disease has been more or less prevalent in the 

nursery. 
The work of identifying the various fungi has not as yet been 
completed. More than five hundred collections were made in 
the Park, Botanic Garden, and Long Island or other points ad- 
jacent to New York. Many of these are duplicates, but approxi- 
mately two hundred and fifty different species of fungi were se- 
