69 
is probably one of the most representative collections of living fern 
plants. This is due to the fact that efforts have been made con- 
stantly to obtain as large a selection of different fern families 
and ecological types as possible, and to maintain these collections 
for their general botanical and special research value. At the 
present time, the collection includes most of the very diverse, but 
interesting, aquatic fern families and genera. Among the species 
of ordinary soil culture type, we still have a wide range of the 
forms which are used, or have been used, in the horticultural trade. 
For these and other reasons, the contribution which the Botanic 
Garden can make in maintaining the general collection of living 
ferns is emphasized. There is no other like it in New York City. 
Economic PLANTS 
By Ratpo H. CHENEY 
1. Further study of the taxonomy and flavor qualities of the 
Mints was continued. Additional herbarium specimens and photo- 
graphs were obtained. 
2. Histo-physiological studies of the effects of the plant purines, 
especially caffeine, upon the microstructure of striated muscle under 
excitation, were extended during the summer at the Marine Bio- 
logical Laboratory, Woods Hole, Massachusetts. 
— 
REPORMOnH Wet CURATOR OE PUBLIC 
INSTRUCTION FOR 1939 
To THE Drrecror: 
I present herewith the report of the work of this department 
for thesyear 1939, 
ATTENDANCE 
Grounds.—The total attendance on the grounds was the largest 
in the Garden’s history—1,798,029, as against 1,726,119 of last 
year. This, in spite of the prophecy, voiced by certain experts in 
the early part of the year, that the competitive influence of the 
World’s Fair, in the Flushing Meadows, would reduce the attend- 
ance at metropolitan institutions. [Towever, such cause and effect 
may have actually been the case, for our annual increase has often 
been more than the 4 per cent. (approximately) shown this year. 
