Summary

Condemns theory of Edward Forbes and others that many islands were formerly connected to South America by now submerged continents.

Summary

CD forgets an author [CD himself in Coral reefs] "who, by means of atolls, contrived to submerge archipelagoes (or continents?), the mountains of which must originally have differed from each other in height 8,000 (or 10,000?) feet".

CL begins to think that all continents and oceans are chiefly post-Eocene, but he admits that it is questionable how far one is at liberty to call up continents "to convey a Helix from the United States to Europe in Miocene or Pliocene periods".

Will CD explain why the land and marine shells of Porto Santo and Madeira differ while the plants so nearly agree?

Summary

Criticises at length the concept of submerged continents attaching islands to the mainland in the recent period. Notes drastic alteration of geography required, the dissimilar species on opposite shores of continents, and differences between volcanic islands and mountains of mainland areas. Admits sea-bed subsidence, but not enough to engulf continents. Denies that theory can explain island flora and fauna.

Considers Edward Forbes’s idea a check on study of dissemination of species.