32 SCIENCE PROGRESS. 



Calaba (Guttiferse), but the former is not represented in the 

 Kew Herbarium from the islands, and Brace's specimen of 

 the latter is accompanied by a note to the effect that it was 

 introduced in the Bahamas. Comparatively recent ex- 

 plorations (22 and 23) in the Keys of Florida have yielded 

 some interesting results, to which I will only very briefly 

 allude. Wallace (24), describing the North American 

 flora, says: "When we reach the southern extremity of 

 Florida we still find ourselves in the midst of oaks, sumachs, 

 magnolias, vines and other characteristic forms of the tem- 

 perate flora ; while the birds, insects and land-shells are 

 almost identical with those found farther north. But if we 

 now cross over the narrow strait, about fifty miles wide, 

 which separates Florida from the Bahama Islands, we find 

 ourselves in a totally different country, surrounded by a 

 vegetation which is essentially tropical and generally 

 identical with that of Cuba." 



From the facts given above, it follows that Wallace was 

 quite right respecting the sudden cessation of northern 

 types in Florida ; but a more thorough exploration of 

 Southern Florida has revealed the existence of a large 

 number of essentially tropical plants, common in the West 

 Indies, and having their northern limit in the extreme 

 South of Florida. 



The last of the West Indian Islands to which I have to 

 refer are the Caymans (25), explored by Mr. W. Fawcett. 

 The great Cayman is about 180 miles distant from Jamaica 

 and Cuba, and is only a mere speck of land, seven or eight 

 miles across in its broadest part ; yet its vegetation is 

 evidently the remains of a larger flora rather than a derived 

 one. Mahogany, cedar, logwood and fustic, the charac- 

 teristic trees of the region, form the bulk of the arboreous 

 vegetation. Upwards of 100 species of vascular plants 

 were collected during a short visit, and they included two 

 orchids new to science, namely, DendropJiylax Faivcettii 

 and Schomburgkia Thomsoniana. 



Dr. Urban's proposed general Flora of the West Indies 

 is being preceded by critical elaborations (26) of many of 

 the obscure and difficult genera, especially those numerous 



