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than on any other island of the same size known to me, and the 

 number of individuals is enormous. The columnar branching 

 Piloccreus is often twenty-five feet high ; the melon cactus be- 

 comes two feet long and over a foot thick ; the three-sided 

 climbing night-blooming Cereus formed impenetrable entangled 

 masses on shrubs and trees, but we were not fortunate enough to 

 find it in flower ; the beautiful snowy little Mamillaria, with nearly 

 white flowers, and tufts of bright white wool among its brown 

 spines, is abundant here as on St. Thomas ;.the cochineal cactus 

 (Nopalea) has showy red flowers ; at least five kinds of prickly 

 pear {Opuntid) occur, two of them forming tree-like plants up to 

 fifteen or twenty feet in height, one of these tree cacti being most 

 remarkable in being absolutely spineless. One species of palm 

 is locally abundant, a silver thatch palm (Coccothrinax) with a tall 

 slender trunk bearing a tuft of palmate leaves, silvery white on the 

 underside, and large drooping branches of small black fruits. A 

 gigantic century plant {Agave), native among the cactuses, con- 



of the island. 



While one section of the expedition was exploring Culebra, the 

 most eastern Porto Rican territory, the other visited Mayaguez, 

 on the western end of the island, and made extensive collections 

 in that vicinity, aided greatly by the courtesy of Mr. D. W. May, 

 director of the Agricultural Experiment Station, and by Mr. H. 

 C. Hendrickson, horticulturist of the Station. The higher ele- 

 vations of this district, including the Mesa Mountain, and the 

 Cerro Gordo range, were visited, and the vegetation up to the 

 altitude of 2.500 feet carefully studied; several of the deep 

 ravines were explored, and a good collection of the characteristic 

 plants was made for the herbarium, and the most interesting 

 species were sent home in a living condition for growing in the 



The work of the Agricultural Experiment Station proved inter- 

 esting enough to require a rather extended examination ; the Sta- 

 tion is evidently handicapped for lack of funds, but the collec- 

 tions of bananas, yautias, pineapples, etc., show that very exact 

 and important work is being done. It is unfortunate that the 



