[Read before the Wellington Philosophical Society, 13th September, 1879.]

The scientific world has had its say upon rook-basins and the action of glaciers in scooping out beds of lakes; and some, indeed, venture to work out the solid materials in that manner in such lake-basins as that of Wakatipu, with its surface 1000 feet above the sea, and its bottom 300 feet below the sea-level. I have, however, nowhere read of wind-formed lake-basins; and I, therefore, propose to describe shortly how they may be and are formed.

If we suppose a flat, composed of sandy soil say, more or less covered with vegetation, and on it a slight depression, which may be caused by the action of the wind blowing the loose soil away—in this depression storm-water will lodge. This lodgment destroys the grass and other land-plants which may have been growing on the surface; and when the pool has dried by evaporation, the surface of the depression is in a fit state to be again acted upon by the wind, any aquatic plants which may have sprung up being destroyed by the drying-up of the water. A further deepening and possible enlargement of the pool takes place, and this process goes on until rain again falls and forms a temporary lake. At length the lake may attain sufficient depth to retain its water throughout the year, and then vegetation may spring up round its borders, and a stability of years or of centuries may be attained.

There have been, I think, a considerable number of wind-formed lakes in New Zealand, many of which have been destroyed by the effects of colonization and the introduction of stock. The fires of the settlers, and the grazing and tread of cattle, destroy the vegetation on the shores of the lake, the sand is set blowing, and the lake is either destroyed or altered in position.

I am inclined to think that part of the Wairarapa Lake has been formed by the wind. There is a line of sand-hills on the eastern shore which there is little doubt is composed of sand blow from the lake-bottom when that had dried up. I by no means suppose the whole lake to be wind-formed, because, as a rule, I do not suppose it to have, or have had, a sandy bottom;