6 THE CACTACEAE. 



In the West Indies we have explored all of the Greater Antilles, the Bahamas, 

 the Virgin Islands, St. Christopher, Antigua, Barbados, and Curasao. 



In South America our field study included the most important deserts of Peru, 

 Bolivia, and Chile, and parts of Brazil, Venezuela, Ecuador, and Argentina. The 

 cactus deserts of South America are so extensive and so remote from one another 

 that it was possible to visit only a part of them in the four seasons allowed for 

 their exploration. 



Among many enthusiastic volunteers whose contributions of specimens and 

 data have greatly supplemented our own collections and field studies, the following 

 deserve especial mention: 



Mr. Henry Pittier has made valuable sendings from Colombia, Venezuela, 

 Panama, Costa Rica, and Mexico; Mr. O. F. Cook, from Guatemala and Peru; 

 Mr. G. N. Collins, the late Federico Eichlam, Mr. R. H. Peters, Mr. C. C. Deam, 

 Mrs. T. D. A. Cockerell, Baron H. von Tiirckheim, and the late Professor W. A. 

 Kellerman have sent important collections from Guatemala; Mr. A. Tonduz, 

 Mr. Oton Jimenez, Dr. A. Alfaro, Mr. C. Werckle, and Mr. Alfred Brade, local 

 collectors and naturalists in Costa Rica, have sent much good material from their 

 country; Mr. William R. Maxon has sent new and rare material from Costa Rica, 

 Guatemala, and Cuba; Professor C. Conzatti and his son. Professor Hugo Conzatti, 

 Dr. C. A. Purpus, Dr. Blswood Chaffey, Mrs. Irene Vera, M. Albert de Lautreppe, 

 and the late Mr. E. A. H. Tays have sent us many interesting specimens from 

 Mexico ; Mr. W. E- Safford made a valuable collection in Mexico in 1907 ; E. W. Nelson 

 and E. A. Goldman, who have collected so extensively in Mexico and the Southwest, 

 have obtained many herbarium and living specimens for our use; Mrs. Gaillard, 

 who lived at Panama several years while the late Colonel D. D. Gaillard was a 

 member of the Isthmian Canal Commission, collected interesting cacti, including 

 Epiphyllum gaillardae; the late Dr. H. E. Hasse sent specimens from southern 

 California and Arizona; C. R. Orcutt, the well-known cactus fancier, has aided 

 us in many ways besides sending us specimens from his collections; Dr. R. E. Kunze 

 has frequently sent specimens, especially from Arizona; General Timothy E. Wilcox, 

 for whom Wilcoxia was named, has sent us specimens from the Southwest, while 

 his son, Dr. G. B. Wilcox, contributed several sendings from the west coast of 

 Mexico and Guatemala; Dr. D. T. MacDougal has sent many specimens from all 

 over the Southwest, especially from Mexico, Arizona, and southern California; 

 he has made several excursions into remote deserts, which have yielded interesting 

 results, and has contributed many excellent photographs, quite a number of which 

 are reproduced in this report (Plate i, etc.). Professor F. E- Lloyd, while located 

 in Arizona and in Zacatecas, Mexico, made large collections of living, herbarium, 

 and formalin material, often accompanied by valuable field notes, sketches, and 

 photographs. Dr. Forrest Shreve has sent specimens, especially from northern 

 Arizona and Mr. W. H. Long from New Mexico; Mr. S. B. Parish and Mr. W. T. 

 Schaller have furnished interesting specimens and valuable notes on southern Cali- 

 fornia species; Professor J. J. Thornber has made valuable contributions of material 

 and notes from Arizona; Mr. M. E. Jones, Mr. I. Tidestrom, Mr. Thomas H. 



