CORALS AND CORAL REEFS. 19 
the sea, and others at greater depths, covered with marine 
deposits, These had been specially described by Admiral 
Wharton. It thus happened that, as time went on, the 
marine surveyor was continually discovering numbers of 
those possible foundations for coral reefs, and in this way 
his theory was corroborated. The greatest objection had 
been taken to his views as to the solution of dead coral 
debris within the lagoons, but these, he believed, would also 
be corroborated by further investigations. A careful exam- 
ination of the surveys of Diego Garcia in 1837 and in 1885 
seemed to show that the lagoon had widened in area to 
the extent of two or three square miles, and that it had 
also deepened slightly. With reference to the boring at 
Funafuti, he held that the evidence, so far as published, 
supported his views, for the true reef appeared to be only 
about 40 or 50 feet in thickness, that then a talus composed 
of blocks from the outer edge of the reef had been pene- 
trated, and, finally, the drill had entered a deep-sea’deposit. 
The reef would thus appear to have grown out on a talus 
of blocks, torn from its outer edge. Those who had described 
the island admitted that it had been elevated about four feet, 
and that it had grown seawards; while in his latest account 
of the bore, Professor David said :—‘ While the advocates of 
the Darwinian theory were inclined to congratulate them- 
selves upon the result, Dr Murray’s supporters say that the 
evidence substantiates their views. Professor David con- 
sidered that the last portion of the core obtained weakened 
the subsidence theory.’ Mr Andrews had been for the last 
nine months examining the structure of Christmas Island, 
in the Indian ocean, and he reported that it was an upraised 
atoll, a plateau forming the summit at 1000 feet being the 
bed of the old lagoon ; and he had found that the coral rocks 
rested upon beds of foraminiferal limestone, and these again 
on solid volcanic rocks. During the past year Alexander 
Agassiz had made a most extensive examination of the Fiji 
Islands, and he had come to the following conclusion :—‘ In 
the Fiji Islands, the atolls and islands or islets, surrounded 
in part or wholly by barrier reefs, have not been formed by 
the subsidence and disappearance of this central island, as 
is claimed by Dana and Darwin. ‘The Fiji Islands are not 
