12 MISSOURI BOTANICAL GARDEN BULLETIN 
the Garden, which have been recorded in current numbers of 
the BULLETIN. 
Mounting and Distribution—Nearly 13,000 specimens have 
been mounted and distributed in the herbarium during the 
fiscal year. This number represents mainly the plants re- 
ceived during the year, thus rendering available for immediate 
use the newly acquired material. 
Field Work.—The Curator of the Herbarium made a botan- 
ical expedition to Central America during January, February, 
and March. The countries visited were the Canal Zone, the 
Republics of Panama, Costa Rica, Nicaragua and Guatemala. 
The object of the expedition was two-fold; first, to study cer- 
tain groups of plants in the field and to secure adequate ma- 
terial of them for monographic study ; second, to make a gen- 
eral collection of Central American plants. Approximately 
3000 specimens were obtained on the expedition. This collec- 
tion greatly augments the Garden’s representation of the flora 
of Central America. A complete report of the expedition can- 
not be made at the present time but the collections thus far 
studied contain a considerable number of rare plants and some 
new to science. In addition to the expedition to Central 
America, a limited amount of local field work has been car- 
ried on, and several local botanists and friends of the Garden 
have generously contributed to the herbarium plants of espe- 
cial interest. 
Exchanges——Several important collections have been ac- 
quired by exchange with scientific institutions with which the 
Garden maintains exchange relations and from individual cor- 
respondents. A limited number of duplicate herbarium speci- 
mens have been distributed during the past year. 
Use of the Herbarium by Outside Botanists ——A relatively 
large number of visiting botanists have consulted the her- 
barium at various times during the year. Several loans of 
herbarium specimens have been made to institutions for study 
by specialists in different parts of the country. Dr. Norma 
E. Pfeiffer, Assistant Professor of Botany at the University of 
North Dakota, who for several years has been occupied in the 
preparation of a monograph of the Isoetaceae, based primarily 
on the collections represented in the herbarium, has completed. 
the work, and the monograph was published recently in the 
ANNALS OF THE Missourt BOTANICAL GARDEN. 
