May 30, 1902.] 



SCIENCE. 



857 



literature, largely botanical and horticul- 

 tural. The director's private laboratory is 

 equipped for chemical, microscopical and 

 bacteriological work, and a similarly situ- 

 ated room is fitted up for the laboratory 

 assistant. A well-lighted room with tables, 

 sink, gas connections and other conven- 

 iences is reserved for the use of investiga- 

 tors, and during the past year several rep- 

 resentatives of northern universities have 

 availed themselves of the privileges thus 

 offered. The director, Professor P. H. 

 Rolfs, has extended every possible courtesy 

 to myself and others, and has made the 

 conditions for work well-nigh ideal. Al- 

 though his time is very fully occupied with 

 investigations and experimental work, it is 

 his expressed wish, in accordance with the 

 liberal policy of the Bureau of Plant In- 

 dustry, that qualified investigators should 

 avail themselves freely of the privileges of 

 the laboratory. 



The work now in progress at the Tropical 

 Laboratory includes a continuation of ex- 

 periments interrupted at Eustis, and many 

 others wliich cannot be described here. 

 The production of hybrid oranges with a 

 view to obtaining a variety that is hardy 

 and at the same time possessed of other 

 desirable qualities, the breeding of refined 

 strains of the pineapple, acclimatization of 

 promising varieties of mango and other 

 fruits, the adaptation of Peruvian corn to 

 Florida lands, and experimental cultivation 

 of forage plants, grains, and other plants 

 of economical value from all parts of the 

 globe, constitute a portion of the work un- 

 dertaken, no small part of which has 

 reached a point at which a successful issue 

 may be hopefully anticipated. 



Recurring to the opportunities offered to 

 students of biological problems, more par- 

 ticularly those in which botanists are inter- 

 ested, there are certain lines of work spe- 

 cially favorable for extended study, largely 

 on account of the great wealth of material 



always close at hand. One of these involves 

 further investigation of climatic influences 

 in determining both the range and habits 

 of plant species. The whole matter of 

 acclimatization and the limits within which 

 given varieties are capable of normal de- 

 velopment is of such obvious economical 

 importance that it has become, as already 

 noted, a leading subject of investigation on 

 the part of the Bureau of Plant Industry, 

 but the habits and structures of native 

 species, in evident adaptation to rainfall and 

 other factors, though so striking as to 

 attract the attention of every intelligent 

 obseiwer, . have been very inadequately 

 studied. The great preponderance, in 

 southern Florida, of one particular mode of 

 adaptation to xerophytic conditions and 

 the partial adoption of this form by species 

 not yet fully adapted to their surroundings 

 suggest one of the many fruitful lines of 

 study that are offered here under most 

 favorable conditions. Equally important, 

 and doubtless quite as promising, is a study 

 of soil conditions, which here plainly exert 

 a marked and even determining influence 

 on the vegetation of particular areas. So 

 apparently simple a matter as a demonstra- 

 tion of the origin of the 'hammocks' has 

 not yet been accomplished. Their inter- 

 esting and obvious resemblance to islands, 

 as pointed out by some writers, is highly 

 suggestive, but gives no account of their 

 actual history. 



The investigation of these and similar 

 questions will naturally be accompanied by 

 a more extended comparison than has yet 

 been made of specific and representative 

 forms common to southern Florida on one 

 hand and the West Indies and more north- 

 ern regions on the other. Such a comparison 

 should involve much more than a mere 

 enumeration of common species. Differ- 

 ences of form and habit, requiring for their 

 observation some degree of expert knowl- 

 edge, must be noted where the plants are 



