18 FLORA OF ST. CROIX AND THE VIRGIN ISLANDS. 



tlieory drawn from tlie facts observed in regard to the mutnal relation 

 between St. Croix and the Virgin Islands, tbat geological rcvolntious 

 bave been eqnally or perbajfs even more powerfully iuHilential in arrang- 

 ing tbe distribution of species tban tbe greater or smaller distance, and 

 the similarity of physical conditions. 



A full knowledge of these interesting fact^s can, however, not be ex- 

 pected till a more thorough exi)loration of all the AVest India islands 

 has taken place. Few of them are as yet tolerably well knowu, and it is 

 therefore earnestly to be hoped that such an exploration of all the West 

 Indies may soon be eflected, the result of which will no doubt be of 

 the highest importance both to botany and to all other branches of 

 natural science. 



It generally requires the accumulated study and knowledge of gener- 

 ations before the less palpable and more delicate, but often most impor- 

 tant, facts in natural history can be explained : the West Indies haA'e 

 been comparatively well studied since the middle of the last century; 

 and it would seem well now to follow up the work in order to complete 

 a thorough investigation, which might be used as a basis for the ex- 

 planation of similar facts observed in other and less Y>^ell known parts 

 of the world. 



The flora of the Virgin Islands and St. Croix has been studied by 

 several botanists, some of whom lla^'e published the results of their re- 

 search, which has, however, among the former group, been chiefly con- 

 fined to the Danish islands, the English and i)articularly the Si)anish 

 ones having as yet been onlj- imi^erfectly explored. 



Publications on the flora of these islands are given by West in his 

 Description of St. Croix (Copenhagen, 1793); Schlechtendal, Florula 

 Ins. St. Tliomfe, in Linmea, 1828-31 and 1831; and Eggers, Flora of St. 

 Croix, ni the Vidensk. Medd. fra Naturhist. Forening (Copenhagen, 1876) 

 besides minor contributions in Vahl's Eclogne Americaufe, Symboloe Bo- 

 tan icse, and Enumeratio Plautarum, Krebs in Xaturh. Tidsskrift, 1817, 

 on the flora of St. Thomas, De Candolle's Prodromus, and Grisebach's 

 Flora of the British West India Islands. This latter work, no doubt 

 from want of material, scarcely ever mentions the British Virgin Islands. 



Collections of plants from tlie islands in question are found chiefly in 

 the Museum of the Botanical Garden in Copenhagen, as well as scat- 

 tered in other European herbaria, collected principally by v. Robr, West, 

 Dr. Ryan, Ledru, Riedl(5, L'Herminier in the past century, by Benzon, 

 Wahlmauu, Ehrenberg, Dr. Eavn, Dr. Hornbeck, Duchassaing, Schom- 

 burgk, Plee, Wydler, Orsted, Krebs, and Eggers in the present. 



