Since the publication, several years ago, of my paper on the relationship of rostro-carinates to certain Lower Palaeolithic handaxes, a great deal more evidence bearing on this matter has come to light. I have been able to examine large numbers of handaxes, found in this country and in very widely separated places abroad, which exhibit, in their profile and in other characteristics, an extraordinarily close resemblance to rostro-carinates. Such palaeolithic specimens I have called rostrate hand-axes, and their number and wide distribution are beyond dispute. If it is a fact that the rostro-carinate is the ancestral form from which the earliest hand-axes were developed, then it would be reasonable to suppose that the oldest group of these, being nearest in time to the rostro-carinate epoch, would contain the largest number of specimens of the rostrate hand-axe type. Moreover, it would be expected that, in the later hand-axe groups, traces of the ancestral form would gradually fade out, and, except for certain specimens of what may be called atavistic form, be eliminated. That is the theory, and it is sometimes the fate of theories to be killed by facts, but in the case under consideration the reverse holds true. For few things in prehistoric archaeology are clearer than that rostrate hand-axes are most numerous in the Early Chelles period, or that the traces of the rostro-carinate form become ever less in evidence in the later epoch of St. Acheul. Though this is the case, however, the matter is not so simple and straightforward as was perhaps at first supposed.