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level of dry land us it now appeal's. So much then for this theoiy. 

 He might say that the latest voluminous writer on the subject — 

 a Hungarian, he believed, named irojsisovics — -differed from 

 Richthofen in two or three things, but accepted the coral theory 

 entirely. He had taken the trouble to trace out all the occurrences 

 of the " Schlern Dolomite " marked on Mojsisovics' maps and 

 transferred them to the chart then v.i view. He thought they 

 would like themselves to form some opinion on the coral island 

 theory, and so he got Professor Darwin's book on coral reefs, atolls, 

 and islands ; and, in order that there should be no temptation to 

 make things agree, he (the speaker) extracted the Dolomite 

 mountains on one chart, while their Secretary extracted the coral 

 islands from Mr. Darwin's frontispieces on another sheet. Neither 

 of them saw each other's drawings until they were finished, but 

 the similarity of the results were now apparent. If anyone should 

 ask him how a circular coral reef could become a solid mountain 

 he should reply, " That is not our difficulty. That is tlie difiiculty 

 of the coral people." How could a circular reef become a coral 

 island ? "VVe had coral islands which are solid masses of coral ; 

 Barbadoes, for instance. The late Professor Froude, driving across 

 it — it is about twenty miles across — said the top was remarkably 

 level and reminded him of driving across the Isle of Thanet, 

 giving an instance of a flat-topped coral island. Mr. Darwin 

 easily solved the difiiculty. He said an atoll may become a coral 

 island, first, by " filling in." As the breakers beat upon the circle 

 they carried over sand, shells, &c., and pieces of coral from the 

 reef itself; thus the central lagoon would be filled in and the 

 whole would become a solid mass, and thus an island would be 

 formed. Then he pointed out that the dash of the waves and the 

 beat of the sea was essential to the health of tliose polyps. They 

 could not thrive in still water, and there was a continuous growth 

 outwards. The coral would have a tendency to e.Ktend outwards, 

 from the fact that the polyps were healthy, and build out against 

 the fresh sea water. Some one made an experiment as to the rate 

 of growth of these coral formations. A number of lumps of corai, 

 each weighing lOlbs. were deposited in the sea, and it was found 

 six months afterwards that they had grown three feet upwards. 

 That is to say that in one year they would have grown six feet, 

 and in 1,000 years they would have grown C,000 feet ; about 

 the thickness of tlie " Schlern Dolomite " in the Langkofel. So 

 that as far as time went they would not have taken a long 

 geological period to foim such a mass. The stratification was not 

 nearly so marked as in the Dachsteiu Dolomite. But what did 

 Darwin say about stratification of coral ? If a coral island were 

 bored through it would be found stratified all the way, and this 

 would give those indications "falsely appearing" as if the islands 

 had been united. That was his doctrine of corals, and tbe 



