4 PREFACE. 
Agriculture. The task has been a laborious one, far more laborious 
than the printed results suggest, but in the progress of the work its 
necessity has been amply demonstrated. The result is a substantial 
basis for the uniform designation of economic tropical plants in accord- 
ance with the system now followed by American botanists. 
Mr. Safford is indebted to Dr. Barton W. Evermann, of the Bureau 
of Fisheries, for photographs Nos. 1, 20, 22, and 44, taken by Dr. 
Alfred G. Mayer, of the Agassiz Expedition to the Tropical Pacitic, 
while attached to the U.S. Fish Commission steamer A/hatross,; to 
Mr. William Bengough for photographs Nos. 2, 7, 8, 28, and 60, taken 
by him on the island of Guam in 1900; to Lieut. Commander J. K. 
Craven, U. 8. Navy, for photograph No. 19; to Lieut. L. M. Nulton, 
U.S. Navy, for photographs on plate 21; to Dr. Harvey Whittaker, 
late of the U. S. Navy, for photograph No. 24; to Mr. B. J. Howard, 
of the Bureau of Chemistry, U.S. Department of Agriculture, for 
photographs on plates 9, 10 (fig. 1), 11, 12, and 13; to Mr. F. Li. Lew- 
ton, of the Bureau of Plant Industry, U.S. Department of Agricul- 
ture, for photograph No. 35, taken in Johore for the Government 
exhibit at Chicago; to Mr. Carl S. Scofield, of the U. 5. Department 
of Agriculture, for photographs Nos. 5, 50, and 57, taken from herba- 
rium specimens from the island of Guam; to Mr. C. B. Doyle for 
photographs Nos. 8, 4, 10 (fig. 2), 31, 32, 38, 40, 41, 42, 46, 47, 49, 51, 52, 
58, 54, 56, 59, 61, 62, 64, 65, 68, from herbarium specimens, for No. 
15 from the seed collection, and No. 14 from cultivated specimens, 
taken under the supervision of the author, and No, 17 from specimens 
collected in Guam by Lieut. Franck Taylor Evans, U. 5. Navy; to 
Messrs. O. F. Cook and Guy N. Collins for Nos. 6, 25, 26, 29, 33, 34, 
43, 44, 48, 55, 58, and 66, taken in Porto Rico, Nos. 27, 30, 36, 39, 
taken in Guatemala, and Nos. 28 and 67, taken in Mexico; and to Mr. 
Guy N. Collins for Nos. 16, 37, and 63, taken in the Hope Gardens, 
Kingston, Jamaica. He is also indebted to Mr, Charles M. Mansfield 
for photograph No. 69, taken from herbarium specimens sent to the 
author from Guam by Rev. José Palomo. 
Through the courtesy of Professor Willis LL. Moore, Chief of the 
Weather Bureau, an account of the climatology of Guam is also pre- 
sented, the detailed study of which is the work of Dr. Cleveland 
Abbe, jr. 
FREDERICK V. COVILLE, 
Curator of the U. S. National Herbarium. 
