“Admitting,” he says, “that in the beginning the lithosphere bulged up in places, so as to form continents, and sagged in other places, so as to form ocean beds, there are interesting problems presented as to the permanence of land and seas. All will admit marginal changes affecting large areas, but these encroachments of the sea on the continents and the later retreats may be of quite a subordinate kind, not implying an interchange of deep-sea bottoms and land surfaces. The essential permanence of continents and oceans has been firmly held by many geologists, notably Dana among the older ones, and seems reasonable; but there are geologists, especially palæontologists, who display great recklessness in rearranging land and sea. The trend of a mountain range, or the convenience of a running bird, or a marsupial afraid to wet his feet seems sufficient warrant for hoisting up any sea bottom to connect continent with continent. A Gondwana Land arises in place of an Indian Ocean and sweeps across to South America, so that a spore-bearing plant can follow up an ice age; or an Atlantis ties New England to Old England to help out the migrations of a shallow-water fauna; or a ‘Lost Land of Agulhas’ joins South Africa and India. “It is curious to find these revolutionary suggestions made at a time when geodesists are demonstrating that the earth’s crust over large areas, and perhaps everywhere, approaches a state of isostatic equilibrium, and that isostatic compensation is probably complete at a depth of only 76 miles” ... and (having noted the difference of density that must exist between the continental, and submarine, earth columns) Coleman would have us bear in mind “that to transform great areas of sea bottom into land it would be necessary either to expand the rock beneath by several per cent or to replace heavy rock, such as basalt, by lighter materials, such as granite. There is no obvious way in which the rock beneath a sea bottom can be expanded enough to lift it 20,000 feet, as would be necessary in parts of the Indian Ocean, to form a Gondwana land; so one must assume that light rocks replace heavy ones beneath a million square miles of ocean floor. Even with unlimited time, it is hard to imagine a mechanism that could do the work, and no convincing geological evidence can be brought forward to show that such a thing ever took place.... The distribution of plants and animals should be arranged for by other means than by the wholesale elevation of ocean beds to make dry land bridges for them.” (Smithson. Inst. Rpt. for 1916, pp. 269-271.)