This is the second volume of the new series of publications dealing with the discoveries made at Olduvai Gorge since 1951. The title of the first volume included the dates ‘1951–1961’. These have been dropped from the present volume, and will also not occur in the remainder of the series, since, inevitably, data obtained since 1961 will need to be included. The next two volumes in this series will deal with the cultural sequence and excavations of the ‘living floors’ in Beds I and II, at Olduvai, by Mary D. Leakey, and the detailed geology of the deposits exposed in the Gorge by Richard L. Hay. It is not yet certain which of the two will be ready for publication first.

A fifth volume is in preparation by Phillip Tobias, the author of this volume on ‘Zinjanthropus’. In it he will describe, in detail, the fossil hominid remains from Olduvai that are attributed to Homo habilis, and to Homo erectus, as well as the new mandible of an australopithecine of ‘Zinjanthropus’ type from Peninj, north of Olduvai. The fifth volume will also include chapters dealing with the postcranial hominid material from Olduvai by Dr John Napier, Dr Peter Davis and Dr Michael Day.

In the present volume, my friend and colleague, Phillip Tobias, has produced a truly magnificent piece of research—a major contribution to the study of the anatomy of the australopithecines, or ‘near men’ as I call them.