CORALS AND CORAL REEFS. ily § 
with which Sir John Murray’s name is now always asso- 
ciated, have led to a partial abandonment of the views put 
forward by Darwin, and to the belief that coral reefs occur 
chiefly in areas undergoing upheaval. Some few people, 
indeed, deny that it is possible for coral reefs to occur at all 
in any area undergoing subsidence. But it does not follow 
that because some coral reefs, and perhaps the majority, 
occur in areas of upheaval, that none can possibly occur in 
areas undergoing subsidence, or that are stationary. The 
vertical growth of coral reefs is limited upward by high- 
water mark, and downward by the depth to which the 
temperature suitable for the growth of the coral extends. 
It is difficult to see why, in a subsiding area, coral growth 
should not spread from the periphery inward over the old 
coral, whose surface was limited by the former high-water 
mark, and why it should not continue to do so if the other 
circumstances are favourable—the growth of the coral 
keeping pace with the subsidence. 
I certainly doubt whether coral reefs can go on growing to 
an indefinite extent on land that is stationary in level, for 
the peripheral growth must soon be checked or even stopped 
by deep-water conditions. Moreover, in the case of a very 
old reef, it is difficult to see what is to prevent the severance 
by solution of the older portion from the zone of original 
attachment. The process of severance, one would think, 
must be somewhat like that of the melting of the ice-foot 
in the Arctic regions. If this really does take place, the 
severance would be followed by the subsidence of the ring 
of coral itself. 
In the majority of cases it will be evident to any one 
who is willing to admit that, for once, our great master in 
Natural Science might be mistaken, that coral-reef areas are 
not necessarily areas undergoing subsidence. The evidence 
upon this is in some cases quite clear, and it is simply a 
matter of time before the view advocated by Murray, or 
some modification of that view, shall meet with general 
acceptance. 
Murray’s view is now well known, but its chief features 
may be again presented in a brief form here as they ap- 
peared in the Scotsman of the 5th of April 1898, after 
VOL. I. 2 
