FLORA OF THE GALAPAGOS ISLANDS. 



253 



TABLE IV. — Pteridophttes and Spermatophttes Common to the 



Different Islands. 



Botanical Evidence regarding the Origin of the 

 Galapagos Islands. 



Two views have been advanced regarding the origin of the Galapagos 

 Islands. According to the first they are pelagic islands, built up from 

 the sea-floor by volcanic action, while according to the second view they 

 are continental islands, tops of mountains, formerly a part of the main- 

 land, now separated from it by subsidence. The first view, namely, that the 

 Galapagos are islands of elevation, was held until about 1890 with scarcely 



