“This remarkable phenomenon,” says Captain Osborn, “opens a vast field for conjecture, and the imagination becomes bewildered in trying to realise that period of the world’s history when the absence of ice and a milder climate allowed forest trees to grow in a region where now the ground-willow and dwarf-birch have to struggle for existence.” Sir Roderick Murchison came to the conclusion that all those trees were drifted to their present position when the islands of the arctic archipelago were submerged. But it was the difficulty of accounting for the growth of trees in such a region which led him to adopt this hypothesis. His argument is this: “If we imagine,” he says, “that the timber found in those latitudes grew on the spot we should be driven to adopt the anomalous hypothesis that, notwithstanding physical relations of land and water similar to those which now prevail, trees of large size grew on such _terra firma_ within a few degrees of the north pole!—a supposition which I consider to be wholly incompatible with the data in our possession, and at variance with the laws of the isothermal lines.”[134] This reasoning of Sir Roderick’s may be quite correct, on the supposition that changes of climate are due to changes in the distribution of sea and land, as advocated by Sir Charles Lyell. But these difficulties disappear if we adopt the views advocated in the foregoing chapters. As Captain Osborn has pointed out, however, Sir Roderick’s hypothesis leaves the real difficulty untouched. “A very different climate,” he says, “must then have existed in those regions to allow driftwood so perfect as to retain its bark to reach such great distances; and perhaps it may be argued that if that sea was sufficiently clear of ice to allow such timber to drift unscathed to Prince Patrick’s Land, that that _very absence of a frozen sea would allow fir-trees to grow in a soil naturally fertile_.”[135] As has been already stated, all who have seen those trees in arctic regions agree in thinking that they grew _in situ_. And Professor Haughton, in his excellent account of the arctic archipelago appended to McClintock’s “Narrative of Arctic Discoveries,” after a careful examination of the entire evidence on the subject, is distinctly of the same opinion; while the recent researches of Professor Heer put it beyond doubt that the drift theory must be abandoned. Undoubtedly the arctic archipelago was submerged to an extent that could have admitted of those trees being floated to their present positions. This, as we shall see, follows from theory; but submergence, without a warmer condition of climate, would not enable trees to reach those regions with their bark entire.