32 E. C. ANDREWS. 
supporting, the translatory movement of matter being 
very slight. 
With the periodical revival of wave movement: the 
western areas have gradually adjusted their opposing forces. 
whereas in the eastern and less stable earth waves the 
zone of rock flowage has provided facilities for establishing 
connection between the greater depth of the crust and the 
surface. 
The main undulations under consideration rise to very 
variable heights and are thus discontinuous along their 
crests so far as the general ocean elevation is concerned. 
They are, moreover, divided into secondary groups, each 
of which tends to reproduce within itself the phenomena 
of increasing instability of form with progressive distance 
from the western zone. HWxamples of this action are Fiji 
and Tonga which tend to produce within themselves an 
epitome of the great earth wave series from the Leeuwin 
to the Tongan Trench. 
Application of Foregoing. 
With the evidence adduced above it is permissible, per- 
haps, to infer the origin of the coral reefs of the Pacific. 
The other great coral reef areas of the world may be 
explained in a similar manner. Thus from Vaughan’s 
clear sighted observations it would appear that the Antil- 
lean area is, from a structural point of view, a bay of the 
Pacific region, a concave curve connecting the great con- 
vexities of North and South America along the same 
continuous structural line of Kainozoic Age. The Indian 
Ocean types, both geographically and geologically, are 
similar also to those of the Pacific. 
The Tertiary limestones which contain corals have been 
deposited as beds in areas of subsidence which, in turn, lie 
1 This has proceeded periodically since Archzozoic time. 
