No one with a taste for strange country can fail to be impressed by the remark? able geography of the Andes of Southern Patagonia: the labyrinth of fjords which split the Chilean coast and bite deep into the mainland; the curiously similar pattern of lakes on the opposite side, many of which, Lagos San Martin and Buenos Aires for example, though lying well to the east of the main range, are drained by rivers flowing through it into the Pacific; the innumerable glaciers which radiate from the central ice caps and thrust their massive fronts into the intricate system of waterways surrounding them. That so much of the region remains unexplored is due almost entirely to its physical difficulties, for during the last sixty years many attempts have been made to penetrate it. Most parts of the main range, even on the eastern side, can only be reached by amphibious operations which are liable to be rendered hazardous by the violent and prolonged storms which prevail. The glaciers in their lower reaches are often so broken and crevassed that it is impossible to travel on them; lateral moraines rarely offer an easy line of approach, and the forest, which covers all but the steepest slopes and extends to an altitude of about 3000 feet, is usually dense, trackless and difficult to negotiate. Except on parts of the ice caps where sledges might possibly be used, back-packing is the only means of transport, and no porters can be hired locally to help with this. But the chief problem is presented by the prolonged periods of rain, the rarity and brevity of spells of fine weather and, above all, the savage wind-storms which sometimes con? tinue for weeks at a stretch, with gusts up to 130 m.p.h. It is these obstacles which have prevented most expeditions from achieving more than a very limited objective or covering more than a very small portion of this very large and exceedingly complex field. The redoubtable Salesian priest, Alberto de Agostini, has been a dominant figure in the exploration of the region. He has led no fewer than twelve expeditions to various parts of it, which have contributed the major part of our knowledge of the main range. A few of the high mountains have been climbed, notably the formidable peak of Fitzroy, the ascent of which was made in 1952 by a French expedition led by Lionel Terray. In 1956 H. W. Tilman and two com? panions crossed the range from the Calvo Fjord to the front of the Moreno Glacier on Lago Argentino. The chief objects of the small expedition which I took to the Patagonian Andes during the 1958/59 season were glaciological and botanical. Geoffrey Bratt, who had been with me in the Karakoram the previous year, shared both the initiative and the organization. He planned to make large-scale surveys of various glacier fronts which would serve as a basis for later observers. We invited John Mercer, who had already been twice to the area in which we proposed to operate, to join the party. He was anxious to continue a line of study on the trees bordering the glaciers, designed to ascertain the dates of successive glacial advances. The Trustees of the British Museum lent us the services of Peter James to make a comprehensive collection of plants and lichens, and furnished a grant of money to cover his expenses. We also invited Peter Miles to join us in Argentina to act as liaison officer and to make col? lections of birds and insects. Besides the British Museum, grants were also received from the Mount Everest Foundation and the Percy Sladen Trust, and surveying