This paper is an attempt to review briefly the progress of geological research in an area familiar to zoologists as the classic ground covered by Alfred Russel Wallace, but which is also the field where Dutch geologists have for many years been carrying out valuable work on a much larger scale than has been possible in the smaller areas under British control in the Malay Peninsula and Borneo. There is a considerable amount of geological literature dealing with the Peninsula and Archipelago. In The Geology of Malaya (1931) is a bibliography of that concerning the Malay Peninsula, and in F. H. Hatch's translation of Posewitz's Borneo (1892) will be found lists of the earlier literature dealing with both the British and Dutch portions of that island. In the Malay Peninsula the Journal of the Straits Branch of the Royal Asiatic Society has included scientific papers since the appearance of their first number in 1878; and in 1927 C. E. Wurtzburg produced an index, including an earlier index by W. D. Barnes, of the Journal up to 1915, when the title of the society was changed to The Malayan Branch of the Royal Asiatic Society. In 1930 the Malayan Branch published an exceptionally interesting number containing a translation by H. V. Mills of Manoel Godinho de Eredia's Description of Malacca, Meridional India and Cathay, originally written about 1600 in Portuguese. This is the earliest known publication that can be called scientific about this part of Asia and contains information about tin and gold, also “traces of diamonds and emeralds as Pliny points out” which later workers have not been able to find.