AMERICAN AND WEST INDIAN FAUNA AND FLORA. 113 



of the Isthmus of Darien, of Panama, and of Nicaragua. Cen- 

 tral America and northern South America at that time must 

 have been a series of large islands, with passages leading 

 between them from the Pacific into the Caribbean.^ 



It is further interesting to speculate on what must have 

 become of the equatorial current, or rather of the current pro- 

 duced by the northeast trades. The water banking up against 

 the two large islands, then forming the Caribbean Islands, 

 must, of course, have been deflected north, have swept round 

 the northern shores of the Virgin Islands, Porto Rico, and 

 Hayti, and poured into the western basin of the Caribbean 

 Sea, through the passage between Hayti and Cuba. This water 

 was forced into a sort of funnel, by the five-hundred-fathom 

 line, which constituted the southern line of the great Bahama 

 Island, and connected nearly the whole of the Bahamas with 

 Cuba, forming thus a barrier to the western flow of the equa- 

 torial current ; this current must, therefore, for the greater 

 part, have been deflected north, and either swept in a north- 

 easterly direction, as the Gulf Stream now does, or round the 

 north end of the Bahamas .across Florida, which did not then 

 exist, across the Gulf of Mexico, and into the Pacific over the 

 Isthmus of Tehuantepec. 



While undoubtedly the soundings indicate clearly the nature 

 of the submarine topography, it by no means follows that this 

 ancient land connection did exist as has been sketched above. 

 At the time when the laro-er West India Islands were formed 

 and elevated above the level of the sea, they may have been 

 raised as one gigantic submarine plateau of irregular shape, in 

 which were included the Bahamas, Florida, Cuba, San Domingo, 

 Porto Rico, and the Virgin Islands. Exactly what portions 

 rose above the level of the sea at that time it is difficult to 

 determine, and it may be that at that period the islands, while 

 larger perhaps than they are now, may still have been the same 

 ill number, having since been reduced in size by denudation, 

 while the channels between them have been widened. 



^ We should bear iu mind that the India Islands existed, thus leaving a free 

 Windward Islands were probably raised access to the Pacific up to that time, 

 long after the range of the greater West 



