264 ORIGIN OF LIFE IN AMERICA 



subsidences drowned the Antilles to such an extent, accord- 

 ing to Professor Hill, that only the higher summits of Cuba, 

 Haiti and Jamaica remained above sea-level as small islands. 

 The West Indian islands were subsequently raised into a large 

 continuous and connected land. In late Miocene and Pliocene 

 times the gradual and final dismemberment of the Antillean 

 lands took place. Still more recently a further elevation 

 occurred, not sufficient, however, to establish a united 

 Antillean continent. Whether Professor Schuchert* supports 

 Professor Hill's hypothesis of a wide land connection be- 

 tween Florida and Venezuela in late Jurassic times is not 

 clearly indicated in his maps. But during the Cretaceous 

 Period all the West Indian islands except the Bahamas are 

 represented as being entirely submerged. In Eocene times 

 the greater part of Cuba was above sea-level. In the succeed- 

 ing Oligocene Period all the islands, except the Bahamas, 

 once more disappeared. Thenceforth all the Greater Antilles 

 retained their present outlines. Only during the Plio- 

 cene Period was there a land connection between Cuba and 

 Yucatan. All these writers thus concur in the view that some 

 time during the earlier part of the Tertiary Era there was a 

 very profound and widespread subsidence of almost the whole 

 of the Antillean area. Yet, according to Professor Schuchert, 

 the Bahamas, or some land area in the position of the 

 Bahamas, if I correctly interpret his maps, remained above 

 sea-level practically from the earliest Palaeozoic ages to the 

 present day. The idea that there was once a land connection 

 between North and South America along the chain of the 

 Lesser Antilles, Cuba, the Bahamas and Florida is also 

 advocated by Professor Gregory, f though he admits that 

 the area of the Windward islands was submerged at the period 

 when the oceanic deposits of Barbados were laid down. There 

 is no adequate evidence, he thinks, to show that there was 

 more land at any subsequent time in this region than there 

 is at present. 



Now as for the light thrown on these various problems 

 by a study of the geographical distribution of the West Indian 



* Schuchert, Charles, " Paleogeography of North America," Maps 89 

 100. 

 t Gregory, J. W., " Geology of the West Indies," p. 305. 



