Glacier Bay. This expedition was Prof. Cooper’s fourth to this locality, the previous ones having been made in 1916, 1921, and 1929, while the writer had been there once before in 1926.1 Both of us continued our series of observations of the glaciers and the positions of the various ice-fronts. Prof. Cooper also extended his botanical and ecological observations of the growth of vegetation in front of the retreating glaciers as well as the detailed study of such interglacial forests as are exposed to view.

All the ice-fronts were visited and their present positions relative to those noted in the past were observed and recorded by photography and in some cases by triangulation. Soundings were also made in all the principal inlets so that the main features of the submarine contours of the whole of Glacier Bay are now known. An airplane flight was also made over the bay during which photographs were taken of all the principal glaciers.

In general it may be said that the snowfields at low altitudes are shrinking and in some cases rapidly wasting away. The ice streams issuing from higher levels, however, show little change. The observations of the termini of the various glaciers may be summarized as follows : all the glaciers of Geikie and Hugh Miller Inlets are retreating, some very much more than others; Reid Glacier is retreating, but the Lamplugh Glacier issuing from the same snowfield is advancing; the Johns Hopkins Glacier is unchanged since 1926, but the hanging glaciers of the inlet show a surprising divergence in behavior with evidence in two instances of considerable advance since 1929; Margerie Glacier has not changed ; Grand Pacific Glacier apparently advanced between 1926 and 1931, but has since retreated; Rendu Glacier has advanced but is no longer tidal ; Carroll Glacier has retreated ; and all the glaciers and snowfields bordering on Muir Inlet have shrunk, while Muir Glacier itself has retreated about a half-mile since 1929.

1Cooper, William S. The Recent Ecological History of Glacier Bay, Alaska. Ecology, Vol. iv, No. 2, April, 1923, pp. 93-128; No. 3, July, 1923, pp. 223-246; No. 4, October, 1923, pp. 355-365,

Cooper, William S. A Third Expedition to Glacier Bay, Alaska, Ecology, Vol. xii, No. 1, January, 1931, pp. 61-95.

Field, W. Osgood. The Fairweather Range: Mountaineering and Glacier Studies. Appalachia, December, 1926, pp. 1-13.