There can be little doubt, however, that the Piltdown man belonged to a period when the flint industry was in a very primitive stage, antecedent to the true Chellean. It has subsequently been observed that the gravel strata(3) containing the Piltdown man were deeper than the higher stratum containing flints nearer the Chellean type. The discovery of this skull aroused as great or greater interest even than that attending the discovery of the two other 'river-drift' races, the Trinil and the Heidelberg. In this discussion the most distinguished anatomists of Great Britain, Arthur Smith Woodward, Elliot Smith, and Arthur Keith, took part, and finally the original pieces were re-examined by three anatomists of this country.[Z] [Illustration: FIG. 67. Skull of South African Bushman (upper) exhibiting the contrast in the structure of the jaw and forehead. One-quarter life size. Original restoration of the Piltdown skull (lower) made by Smith Woodward in 1913. One-quarter life size.] It is important to present in full the original opinions of Smith Woodward, who devoted most careful study to the first reconstruction of the skull (Fig. 67), a model which was subsequently modified by the actual discovery of one of the canine teeth. In his original description it is observed that the pieces of the skull preserved are noteworthy for the great thickness of the bone, it being 11 to 12 mm. as compared with 5 to 6 mm., the average thickness in the modern European skull, or 6 to 8 mm., the thickness in the skull of the Neanderthal races and in that of the modern Australian; the cephalic index is estimated at 78 or 79, that is, the skull is believed to have been proportionately low and wide, almost brachycephalic; there was apparently no prominent or thickened ridge above the orbits, a feature which immediately distinguishes this skull from that of the Neanderthal races; the several bones of the brain-case are typically human and not in the least like those of the anthropoid apes; the brain capacity was originally estimated at 1070 c.cm., not equalling that of some of the lowest brain types in the existing Australian races and decidedly below that of the Neanderthal man of Spy and La Chapelle-aux-Saints; the nasal bones are typically human but relatively small and broad, so that the nose was flattened, resembling that in some of the existing Malay and African races. [Illustration: FIG. 68. Three views of the Piltdown skull as reconstructed by J. H. McGregor, 1915. This restoration includes the nasal bones and canine tooth, which were not known at the time of Smith Woodward's reconstruction of 1913. One-quarter life size.]