708 Mr. Edwin Ashby on the [ Ibis, lake at Calabona in South Australia and the survival ina shady gorge of the MacDonald Ranges of a species of Fan Palm and a AMacrozamia, both representatives and survivals of a long-distant past when luxuriant vegetation grew there, conclusively support this contention.

A. botanist of high standing has advanced the opinion that the ‘‘ Mallee,” a group of Eucalypts that branch from the base and no longer grow into a timber-tree, are the survivors of an ancient forest. Therefore the thousands of square miles of Mallee now existing are the remains of an immense aberrant forest, dwarfed and stunted during the ages because of the steady decrease in the rainfall.

It is quite certain that the spare, stiff, cardboard-like leaves of these Hucalypts and the very dry character of the districts in which they grow, absolutely preclude the possibility of the generation of sufficient heat by fermentation to hatch such eggs that may be deposited there. I therefore judge that in the long-distant past the Leipoa, in common with its congeners, Megapodius and Alectura, gathered together the leafage and debris that must then have thickly strewn the ground under the trees of the luxuriant forests of those distant days.

But slowly and surely the climate changed, the atmosphere grew drier and drier, the forest-trees diminished in size, until we have the dwarf forms of Eucalypts which we know to-day as Mallee.

If we accept this statement of probable facts as correct— the evidence is so strong that it is well-nigh impossible to deduce otherwise,—we may fill in an unwritten page of the past history of Australia’s Mound-building Birds.

Instead of their method of incubating their eggs being a survival of an old reptilian habit of simply scratching a hole in the sand and leaving the future of their eggs to the influence of solar heat and chance, we have a group of birds who have acquired nighly specialised habits in connection with the incubation of their eggs.

It is impossible to tell whether their progenitors had, in common with most birds, been “ nest-makers,” hatching their eggs by means of body-heat, and then adopted the method of