Seventh Meeting: 5th October, 1910.
Present: Mr. R. M. Laing (President), in the chair, and fifty-five others.
New Members.—Mr. J. A. Pannett and Dr. C. Morton Anderson.
Letter from Dr. W. S. Bruce.—A letter was received from Dr. W. S. Bruce acknowledging the receipt of a copy of the “Subantarctic Islands of New Zealand,” and congratulating the Institute on its production.
Hocken Memorial Fund.—The President drew the attention of members of the Institute to the Hocken Memorial Fund.
Papers.—1. “Note on the Flora of Mount Egmont: a Correction,” by Dr. L. Cockayne (see p. 49).
2. “Additions to the Fish Fauna of New Zealand: Part II,” by Edgar R. Waite (see p. 49).
3. “A Preliminary Phytogeographical Sketch of the Vegetation of the Mount Arrowsmith District,” by Dr. L. Cockayne and R. M. Laing.
The paper deals in the first place with the repopulating of the glaciated areas after the retreat of the ice, using as data the present happenings on river-bed at the terminal faces of glaciers, on débris, and so on.
The various soils are discussed, especially the wind-blown rock-flour, the “loess” of the authors. The climate of the district is classified as steppe and forest climate, and the limits of these are defined.
Wind is cited as an ecological factor of paramount importance.
The mechanical and physiological effects of snow are briefly discussed, also its relation to the installation of steppe or fellfield psychrophytes. Short periods of drought are considered to strongly favour xeromorphy.
The body of the paper deals with the plant-associations, and the growth-forms of their members. The vegetation is treated of from the dynamical standpoint, and the associations fall into two categories—namely, the steppe series and rock-fellfield series, or, in the forest climate, the rock-forest series. It is further shown how the same climax association may arise from different beginnings.
The paper concludes with a list of species noted in the district, arranged according to the system of Engler, and a short bibliography.
4. “The Post-glacial Climate of Canterbury,” by R. Speight.
In this paper the author advances tentatively an hypothesis that during the great extension of the glaciers in Pleistocene times the climate was in all probability steppe-like in character over the eastern slopes of the Southern Alps, and that at a subsequent time it became much moister than at present, this moist climate being succeeded by the present modified steppe conditions. This hypothesis is based partly on geological and partly on biological considerations. The following facts are cited in this connection: Extensive forests once existed over areas which are now treeless and dry; peat bogs appear to be shrinking; the land Mollusca are also of a wet-climate type, and not suited to their present surroundings. It is admitted that the evidence put forward is suggestive rather than convincing, but the author hopes that the paper may serve to draw attention to a question which has attracted considerable attention in other parts of the world, and that some work may be done here to correlate distant changes with those that occurred here—if, indeed, these changes took place.