214 W. M. DAVIS 
plateaus [submarine banks, here assumed to be the product of abrasion during 
the glacial period], their accordant relation at present sea-level, and the impossi- 
bility of explaining them by any cause other than prolonged marine action [on 
still-standing preglacial islands of similar area], are the supreme facts empha- 
sized in this paper. The weakest element in the subsidence theory is its failure 
to take account of them [221, 222]. 
Even in regions where Tertiary deformation is recognized, post- 
Tertiary subsidence is doubted, if not excluded. For example: 
New Caledonia and the Fiji Archipelago are generally regarded as located 
in a region of continental fragmentation. During the Tertiary period the 
eastern part of the Australasian continent was much faulted and otherwise 
deformed; the already dissected region sank beneath the sea and many valley 
bottoms became covered with water, scores or hundreds of meters in depth. 
. . . . Some bays of central islands [within barrier reefs] in the Western Pacific 
are explained [by Dana and others] by the sinking of those islands. However, 
the dating of that subsidence is not yet established and the actual bays may 
be due to the Pleistocene cleaning out of unconsolidated sediments which had 
been deposited in valleys, drowned during the Tertiary fragmentation of the 
Australasiatic continent. .... / A similar explanation [of bays by subsidence] 
cannot be admitted for most of the coral archipelagoes. These lie outside of 
the Fiji-New Caledonia area [224, 226]. 
As to the implication in the last sentence that the embayments of 
reef-encircled volcanic islands in the Caroline and Society groups 
should not be explained by subsidence, I shall at this time only 
express my dissent fromit. The object of the present paragraphs is 
to emphasize the contrast between the elasticity of the fundamental 
postulate of intermittent subsidence in Darwin’s theory and the 
rigidity of the fundamental postulate of widespread and prolonged 
crustal stability in the glacial-control theory. Inquiry will be 
made later into the necessity of such contrast. 
Possible subsidence of volcanic islands.—There is another aspect 
of the contrast between the two theories here under discussion that 
merits special consideration. This is the relation of many coral 
reefs to volcanic islands that rise from the deep ocean floor far from 
any continent; for it is generally agreed in all theories of coral 
reefs that even the foundations of atolls, where no volcanic rocks 
are visible, nevertheless consist of submarine volcanic cones and 
thus resemble the foundations of pelagic barrier and fringing reefs, 
where the volcanic cone is partly emerged. Darwin’s theory of 
