12 E. C. ANDREWS. 
‘different portions of one island. In exceptional cases the upheaval 
is wanting, and even subsidence may occur instead, as has been 
explained above. 
The consecutive phases of development of the anticlinal portions 
of the folds are revealed at the surface by the mode of develop- 
ment of the reefs, and can be studied by comparing the character 
and the relative position of extinct reefs of the same age.” 
Darwin’s conception of coral growth during subsidence 
of the basins of both Pacific and Indian Oceans was capti- 
vating in its simplicity and found ready champions in the 
authors named above, namely, Dana, David,! and Davis. 
David’s ideas are crystallised partly in his classic mono- 
graph on Funafuti and in the exquisite model, to scale, of 
the atoll even to its base at the points of confluence with 
the Pacific Ocean floor. 
Davis considers the islands and lands associated with 
coral reefs as so many silent witnesses of the great coral 
drama being enacted within the tropic seas, and he seeks 
to decipher the history of coral growth from the evidence 
of their written but unspoken testimony. His conclusion 
‘is that the coral reefs of the Pacific have been formed dur- 
ing periods of submergence of the various islands of the 
Pacific. On the other hand he establishes his point that 
each island bas had an individual structural history. 
These studies of Davis, illustrated by block diagrams, 
form one of the most valuable contributions to our know- 
ledge of the Pacific Islands, and his explanations of “‘plung- 
ing clifis,’’ the variable heights of associated coral islands, 
of atolls associated with embayed islands, forming the 
centre of the lagoons in certain cases, as of dissected 
volcanoes, have assisted in a marked manner in the eluci- 
dation of the coral reef problem. 

1 These remarks apply only to David’s published views of Funatuti. 
