AMERICAN AND WEST INDIAN FAUNA AND FLORA, 117 
have acted upon oceanic islands. The proximity of these islands 
to a great continent has, however, intensified the efficiency of 
these causes. 
Among the oceanic islands which show most clearly the effects 
of ocean currents and of winds on the distribution both of ma- 
rine and of terrestrial animals and plants, the Bermudas are 
the most interesting. Situated in the very track of the Gulf 
Stream, we readily trace to their origin a host of littoral marine 
animals and many plants, known to us from the investigations 
of the older naturalists, in the West Indies and the northern 
shores of South America ; while the more recent investigations 
have shown the community of origin of a number of rarer Ber- 
mudan types with forms found in the deeper waters of the Ca- 
ribbean Sea, the young of which are carried northward during 
their pelagic embryonic stages, with the seeds of many of the 
plants which have become acclimated in the Bermudas. 
The fact that the Bermudas are of comparatively recent ori- 
gin shows how varied the fauna and flora of a group may 
become when placed in the path of a current or of prevailing 
winds, and how comparatively little time is required for the 
acquisition of faunistic characters which may closely link the 
group to distant shores. Were the conditions of winds and 
currents changed, we might be tempted to explain these charac- 
ters upon the theory of former land connections, which perhaps 
never existed. 
The vegetation of the Bermudas is thoroughly Floridian and 
West Indian, consisting of palmettos, mangroves, junipers, limes, 
ete.; and we can easily see how the seeds or shoots of many 
plants can have been brought by the Gulf Stream and settled on 
the low shores of the islands when they once rose above the level 
of the sea. There are no mammals except the rats and mice 
imported with vessels. The birds are not numerous; they are 
common North American species, of which only a few breed 
on the island, while there are other annual visitants. The 
only land reptile known there is closely allied to, if not iden- 
tical with, a species of skink inhabiting the Carolinas, and the 
marine fauna and flora are West Indian. The large tuctles of 
the coast of Florida, the fishes, mollusks, crustacea, polyps, and 
