IN 1892–3 Dr. W. Michaelsen conducted a zoological collecting expedition to the south end of South America, and was remarkably successful as regards booty. Descriptions of his collections began to appear in 1896, and they are now gathered together in three substantial volumes, each of several hundred pages. Dr. Michaelsen gives a lively account of his journeyings, and Prof. Dr. G. Pfeffer, of Hamburg, who persuaded some of his enlightened fellow-citizens to subsidise the expedition, refers briefly to the general bearing of the various contributions. It seems to us a matter for regret that there is no adequate summation of the results of the expedition, though we do not know what more Dr. Pfeffer could have done within the limits allotted to him. It is certainly very difficult to deal with a huge bundle of memoirs, by about forty different authorities, and bearing diverse dates from 1896 to 1907. We cannot do more than give a general indication of the contents of these volumes.