The occurrence of diminutive flint implements in certain industries of the Stone Age has been recognized for many years. Such specimens have been supposed to make their first appearance in the Upper Aurignac (Late Palaeolithic) period; to have extended sparingly through the Solutre and La Madeleine epochs; and to have become very numerous in the transitional industrial stages between the latest palaeolithic and earliest neolithic horizons. This, we think, is a fair statement of the opinion held by the majority of present-day archaeologists. There are, however, on record certain discoveries of diminutive flint implements in deposits older than those of the Upper Aurignac period. Search has been made for notices of previous discoveries, but material available is unfortunately small. In 1908 M. Eugene Pittard announced the discovery, in the valley of the Rebieres, Dordogne, of what he terms a microlithic industry in flint of Lower Le Moustier age. The site is in the open air, and the section exposed contained both Le Moustier and Aurignac levels of occupation. The microlithic industry was found at the base of the deposits, beneath Le Moustier horizons. M. Pittard figures some 40 specimens, and there seems no doubt that these represent very small but definite implements made to fulfil some special purpose. His excellent illustrations show that these resemble a series discovered in a dry valley to the north of Ipswich some years ago. These specimens will be described later, and possibly some of them are contemporary with M. Pittard's implements. The only other reference we can find to the discovery of very small implements before the Upper Aurignac period is in one of the many papers published on the remarkable finds at Chou Kou Tien, near Peking, China. In the limestone caves and fissures at this place have been found numerous fragments of skulls and jawbones of a primitive race of man to which the name of Sinanthropus has been given. Associated with these relics was a large number of stone implements, made of various rocks, of peculiar and somewhat unfamiliar types.