Jones supposes that the light color of these so-called mummies of Tennessee and Kentucky was due to the action of lime and saltpetre.[276] We have every reason to believe that the men of the mounds were capable of executing in sculptures reliable representations of animate objects. The perfection of the stone carvings, as well as the terra-cotta moulded figures of animals and birds obtained from the mounds, have excited the wonder and admiration of their discoverers. It was evidently a favorite pastime for those primitive artists to reproduce the human features, for effigies and masks have often been exhumed together with other sculptures. The perfection of the animal representations furnish us the assurance that their sculptures of the human face were equally true to nature.[277] The accompanying figures of sculpture and masks together with those found in the sculpture of the Mayas and Nahuas, shown in a future chapter, furnish us with a twofold argument: first, that an American type of physiognomy as such did not exist; that, upon the contrary, it was as variable and diversified as can now be found among the peoples of Europe or elsewhere; second, that a strong resemblance between some of the sculptures of the mounds and those of Mexico exist. It is a remarkable fact that those of Palenque furnish the most striking likeness to those of the Mississippi Valley.[278] There is, perhaps, no means of ascertaining of what color the pre-historic Americans were, certainly not of the Mound-builders; but judging from the great variety of tints and shades that prevail among the wild tribes of North America alone, we may conclude that no argument in favor of an _American_ race can be based upon color.[279] [Illustration: Mound Sculptures: upper left-hand figure from a shell-heap near Mobile, Ala., the others from Tennessee mounds.]