between Cape York and the nearest part of New Guinea shows, not only a number of islands of some size, but innumerable islets and reefs studding a sea so shallow that there is only exceptionally a depth of lo fathoms in the channels. A movement of elevation of 60 feet would therefore connect Australia and New Guinea, and a re-elevation of the 80 to 100 feet of subsidence in comparatively recent times which Dr. Jack assigns to the north-east coast, would do more than merely connect the two lands.
So far as is yet known, the extinct mammalia to which Dr. Jack refers did not extend into New Guinea, and the absence of the platypus and the feeble development of the polyprotodont fauna in north-eastern Australia is considered by Professor Baldwin Spencer to indicate that they spread northwards rather than southwards,[1] thus negativing the existence of an upraised Torres Strait at that early period.
This suggests that, although there had been a land communication which admitted of a certain migration of Australian forms, it had ceased before the giant extinct marsupials spread into the extreme of Northern Queensland, and according to Dr. Jack that would probably have been in Post-Tertiary times.[2] It seems therefore evident that there was a land communication between New Guinea and Australia at a comparatively recent period by which the Tasmanians, and subsequently the Australians, might have entered this continent. But this would have been anterior to the subsidence of Torres Strait as we now see it.
Thus all the evidence I have been able to collect points to there having been a more practicable line of migration by way of New Guinea than by Timor.
At present too little is known of New Guinea to enable anything to be said as to existing traces of the Tasmanian and the Australian stocks in that island. But it is to be noted that New Guinea, Australia, and Tasmania were during our time, and as to the two former, still are occupied respectively by well-defined types of man, effectually separated
