14 PROCEEDINGS OF THE INDIANAPOLIS MEETING. 



On this point it is difficult to acquit some of the extreme advocates of the theory of 

 the charge of reasoning in a circle. Whenever a case is quoted of sedimentary rock 

 at a great distance from the main land, and with deep water intervening, they assert 

 that it is not, for that Vf,ry reason, an oceanic island. Though it may be rather diffi- 

 cult exactly to define what shall constitute an oceanic island, it is easy to quote exam- 

 ples of what must be such islands, if the term is to mean anything at all, in which, 

 nevertheless, stratified rocks occur. Let us mention a few : 



It is scarcely necessary to linger over the oft-quoted case of the Seychelles — a granite 

 group separated from Africa by a channel 2,000 fathoms deep ; or on the various 

 islands of the East Indian archipelago, some of which are certainly entitled to the 

 name. Less frequently cited perhaps are New Caledonia, between which and Aus- 

 tralia lies a channel 700 miles wide and 2,000 fathoms deep ; New Zealand, 1,200 

 miles from Australia, with 1,000 fathoms of water between them ; the Falkland 

 islands, 600 miles from the South American continent, and South Georgia, 800 miles 

 farther still, in the same direction, and yet containing rocks of clay slate. But per- 

 haps the strongest case of all is that of Kerguelen land (the Desolation island of Cap- 

 tain Cook), midway between the Cape and Australia, and 2,000 miles from both, yet 

 containing sandstone and coal and, according to Sir Joseph Hooker's by no means 

 surprising statement, a flora of immense antiquity. 



Furthermore, in the same direction it may be urged (though our limits allow little 

 more than the suggestion) that the scarcity of such islands is only what should be ex- 

 pected under the circumstances. Sink the continent of North America to the depth 

 only of 1,000 fathoms, and what would remain above water to tell that it had existed ? 

 Not a single spot in all the eastern and midland region would be visible. The western 

 mountainous area would in places be dry. But sink it to the depth of the Atlantic, 

 or to 2,500 fathoms, and nearly everything would be lost. Not a peak of the Rockies, 

 with one or two doubtful exceptions, would remain above water, and those would be 

 volcanic. A few of the Mexican volcanoes also would survive. It is scarcely sur- 

 prising therefore that so few except volcanic islands can be found in the present oceans, 

 even if they should be the sites of sunken continents. Their scarcity cannot be em- 

 ployed as a strong argument in favor of permanence, 



{d) The fourth of the leading arguments urged in support of the doctrine of per- 

 manence is drawn from the distribution of animals and plants. Instead of enlarging 

 on this as intended, I cannot do better than make a few extracts from the address re- 

 cently delivered by Mr. W. T. Blanford, president of the Geological Society of Lon- 

 don, in which the subject has been treated in a masterly manner. 



Mr. Blanford assumes as a proposition whose truth from the biologic standpoint is 

 axiomatic that New Zealand was formerly connected with Australia, and that the 

 Solomon islands were also connected with New Guinea. He then discusses at some 

 length the affinity of the Malagasy flora. Here, though rejecting the hypothetical 

 " Leniuria " of Tertiary times, he thinks that the well-marked oriental element in 

 the Mascarene fauna and flora requires the existence at a late Tertiary date of large 

 intermediate islands, and is quite prepared to give his adhesion to the doctrine of con- 

 tinuous land at an earlier era. I cannot here repeat his argument in full, but belays 

 great stress on the significant flora that existed in later Paleozoic time from Australia 

 to India and southern Africa, and remarks that a great continent including all these 

 three seems more in accord with facts than Mr. Wallace's view "that fragmentary 

 evidence derived from so remote periods is utterly inconclusive." 



Mr. Blanford 's long experience in India enables him to point out some fj\cts that 

 strongly support the views which he expressed several years ago and to which he 



