Combs — Plants Collected in the District of Cienfuegos. 395 



the islands above water, or, as Belt suggests,* " the land may 

 never have subsided, but the connection with the continent 

 was made by the water having been withdrawn to form the 

 polar ice cap during the glacial epoch, leaving the islands 

 connected with one another and with the continent by what 

 are now submarine banks." This explanation seems hardly 

 probable, since during the glacial epoch the polar regions 

 were greatly elevated, and the southern part of the United 

 Stales region was greatly depressed. This would touch the 

 West Indies, and it is hardly probable that they would be 

 above water when the southern part of the United States was 

 under water. Marine charts of this region show Cuba con- 

 nected with Yucatan, except for a short distance of 15 miles, 

 by a marine bank, covered by a depth of from 600 to over 

 1,000 fathoms of water. 



Cuba and Haiti are connected by a submarine ridge lying a 

 little north of the shortest distance between them, which 

 does not exceed the depth of 900 fathoms; Haiti with 

 Jamaica by one, the extreme depth of which is something near 

 1,000 fathoms, and Jamaica in turn with Honduras at a depth 

 of 1,000 fathoms. On the north, Cuba is connected with 

 the Bahamas at 300 fathoms by the Great Bahama Bank, and 

 the Bahamas are in turn connected with Florida at 500 

 fathoms. Then, as Hitchcock f says, '* if from any cause the 

 depth of the water of the ocean should be lessened by 100 

 fathoms there would be exposed the Little Bahama and Great 

 Bahama banks and several of the smaller banks to the south- 

 east. The Bahamas would be separated from the surrounding 

 islands and from Florida, and the important channels would 

 still occupy the same places. If reduced by 300 fathoms, 

 the Great Bahama bank would be united with Cuba. If the 

 water were 500 fathoms shallower than at present, the Little 

 and Great Bahama banks would be united with Florida and 

 some of the Windward Islands would be connected. It is not, 

 however, till a layer of water 1,000 fathoms deep is removed 

 that important changes would occur. Jamaica would be 



* The Naturalist in Nicaragua, p. 266. 



t Plants collected in the Bahamas, etc., p. 160. 



