48 MISSOURI BOTANICAL GARDEN. 
Agaves is probably the most extensive in the United States. 
It was the scene of Dr. Engelmann's labors. It still con- 
tains many of his plants, and young plants raised from 
them. Its herbarium contains his type specimens, manu- 
script notes, drawings, and reference books, in connection 
with its large collection and library. 
Every possible facility has been afforded me in this study. 
Much trouble has been taken to open correspondence with 
residents in the Agave regions, and to obtain fresh material 
from the field. I am grateful for the opportunities given, 
and very especially so to Dr. Trelease ; had it not been for 
his kindly suggestions, encouragement and assistance, the 
work would not have been possible. 
I have also had the use of the specimens in the Gray 
Herbarium of Harvard University, and the herbaria of 
Columbia College and the United States Department of 
Agriculture. I wish to express my thanks to Dr. Robinson, 
Dr. Britton and Dr. Coville for the use of the material in 
their charge, and to Mr. T. S. Brandegee for the use of 
his private collection. 
Thanks are also due, for much courtesy and assistance, 
to the following persons : — 
Professor P. H. Rolfs, of Lake City, Mr. H. J. Webber, 
of Eustis, Mr. C. T. McCarty, of Ankona, Mr. Kirk Mun- 
roe, of Cocoanut Grove, Florida; Mr. C. G. Pringle, of 
Charlotte, Captain John G. Bourke, U. S. A., of Fort Ethan 
Allen, Vermont; Dr. J. T. Rothrock, of West Chester, 
Pennsylvania; Mr. C. R. Dodge, of Washington, D. C; 
Dr. E. A. Mearns, U. S. A., of Fort Myer, Virginia; Dr. 
B. D. TenEyck, U. S. A., of Eagle Pass, Dr. B. D. Tay- 
lor, U. S. A., of Fort Bliss, Professor C. H. Tyler Town- 
send, of Brownsville, Mr. G. C. Nealley, of Corpus 
Christi, Mr. J. Gilcrease, of Sierra Bhmca, Mrs. Anna 
B. Xickeis, of Laredo, Mrs. Maud 3L Brings, of El Paso, 
Texas; Mr. M. E. Jones, of Salt Lake City, Utah ; Mr. C. 
R. Orcutt, of San Diego, Mr. S. B. Parish, of San Ber- 
nardino, Mr. F. Sutpiiens, of Witch Creek, California; 
