—-_- 
TRANSACTIONS 
OF THE 
SCOTTISH NATURAL HISTORY SOCIETY. 
CORALS AND CORAL REEFS.* 
An Address delivered to the Scottish Natural History Society 
at the Opening of the Session 1898-99. 
By Mr GoopcuiLp, of the Geological Survey, F.G.S., F.Z.5., 
Curator of the Collections of Scottish Geology and 
Mineralogy in the Edinburgh Museum of Science and 
Art, President. 
WHat we commonly understand by corals are organic 
structures consisting mainly of carbonate of lime, which 
the animals that form those structures have extracted 
during their lifetime from sea-water. The primary source 
of that carbonate of lime lies where many people would 
little think of looking for it, for it occurs as one of the 
original constituents of eruptive rocks. Some of these 
rocks, when they rise in a fluid state from the inner zones 
of the earth’s crust, carry upward large quantities of lime in 
a state of solution, and when the aqueous solvents escape 
and the temperature falls, these solutions consolidate, and 
* This Address was illustrated by many large water-colour diagrams of 
living corals and their allies, by numerous specimens illustrating the form 
and the mode of growth of corals, and by a series of lantern slides taken 
from photographic views of living corals and coral reefs, chiefly from views 
taken in the New Hebrides by the Rev J. S, Laurie. 
VOM: 1: I 
