DEPARTMENT OF BOTANICAL RESEARCH. 87 



with one of the larger bundles of the old fruit. It has been determined 

 that the origin of a plantlet from a fallen fruit is not dependent in any 

 way on the presence of seeds in this fruit. If ripe seeds are present 

 they are in no way affected by the process of sprouting of the fruit. 



Another fact to be explained only by the aid of experimental work 

 in the field is that the axillary buds give rise to floirers only so long as 

 they remain attached to the mature plant, while the buds of fallen 

 fruits give rise to roots and shoots only. 



The Relationships and Distribution of the CactacecB, hij N. L. Britton 

 and J. N. Rose. 



In the early part of the year Dr. Britton and Dr. Rose, with a 

 party of assistants, visited some of the West India Islands, where 

 they made large collections of cacti and of plants in general. Col- 

 lections were made on St. Thomas, St. Jan, Tortola, Virgin Gorda, 

 Anegada, St. Croix, St. Christopher, Antigua, Porto Rico, Santo Do- 

 mingo, and Curasao. Especial attention was given to the drier parts 

 of the islands, on account of the greater number of cacti to be found 

 there. The collection of living cacti brought back is undoubtedly 

 the largest ever made in the West Indies. Not only were new 

 species collected, but also species which were heretofore wanting in 

 our collections, having been known only from meager descriptions. 

 Among the most interesting of these are the Cactus mamillaris of 

 Linnseus, found on Curagao, heretofore unknown in American collec- 

 tions, and an Epiphyllum from Antigua, represented only by a draw- 

 ing at Kew. The collections are being grown in Washington and 

 New York City, a part being used for exchange purposes. 



It is fitting to call attention again to the great assistance rendered 

 by volunteer collectors, who have sent in material from all the cactus 

 regions in North America, and to some valuable contributions from 

 South America. Up to the present time more than 100 volunteer 

 contributors have aided in this research. 



The manuscript on the subfamilies Pereskioideae and Opuntioidete is 

 practically completed, with the exception of many South American 

 species which must await further field studies. 



The exploration of the South American deserts is the most impor- 

 tant piece of field work to be undertaken, and plans are now being 

 made to begin shortly the study of the Chilean, Peruvian, and Boliv- 

 ian deserts, to be followed by extensive explorations in .\i'gentina the 

 following j^ear. 



During the j^ear two prehminary papers were published by Dr. 

 Britton and Dr. Rose, in which four old genera were restored and two 

 new genera and eleven new species were described. In one of these a 

 reclassification of Epiphyllum and its allies was given. By the 

 description of these new species considerable valuable material is 

 made available for exchange purposes. 



