(311) 
nually, already specified for the purchase of books, and 
some books may be bought from the income of the Maria 
De Witt Jesup Fund of $25,000, bequeathed by Mrs. 
Jesup and specified for the increase of the collections, while 
others may be had from the Special Book Fund, made 
up of contributions for the purchase of books. The ordi- 
nary increase of the library is thus at least partly pro- 
vided for; some very expensive sets of desirable books of- 
fered for sale at intervals may need to be secured through 
other sources of income. 
As recorded in the report of the Librarian, hereto ap- 
pended, the library now contains just about 30,000 volumes. 
Exploration and Collecting 
A set of the important collections made by Dr. A. S. 
Hitchcock, Agrostologist of the United States Bureau of 
Plant Industry in British Guiana during the latter part of 
1919 and in January 1920, referred to in my last report, 
was received during the summer,* and has since been 
partly studied. I was occupied for about ten weeks in 
the early part of the year in botanical collecting on the 
island Trinidad with a party of assistants;t we obtained 
a fine series of specimens illustrating the vegetation of 
that island, which have mostly been studied and in- 
corporated into the permanent collections. Both Dr. 
Hitchcock’s expedition and mine were carried out under 
the cooperative arrangement entered into by us with the 
United States National Museum and the Gray Herbarium 
of Harvard University for the increase of knowledge of 
the flora and plant products of northern South America 
and adjacent islands.{ This investigation has proved to 
be very important, resulting already in large accessions of 
specimens and of plants not hitherto represented in our 
collections and in new highly valuable scientific informa- 
* See Journal N. Y. Bot. Gard. 21: 129-137. 
t See Journal N. Y. Bot. Gard. 21: 101-118. 
tSee Journal N. Y. Bot. Gard. 19: 182-185. 1918; and Science N.S. 53: 29, 
30. 1921. 
