Page:Geology and Mineralogy considered with reference to Natural Theology, 1837, volume 1.djvu/92

 88 formed in a few years from sand-banks composed of similar materials, on the shores of tropical seas.

Frequent discoveries have also been made of human bones, and rude works of art, in natural caverns, sometimes inclosed in stalactite, at other times in beds of earthly materials, which are interspersed with bones of extinct species of quadrupeds. These cases may likewise be explained by the common practice of mankind in all ages, to bury their dead in such convenient repositories. The accidental circumstance that many caverns contained the bones of extinct species of other animals, dispersed through the same soil in which human bodies may, at any subsequent period have been buried, affords no proof of the time when these remains of men were introduced.

Many of these caverns have been inhabited by savage, tribes, who, for convenience of occupation, have repeatedly disturbed portions of soil in which their predecessors may have been buried. Such disturbances will explain the occasional admixture of fragments of human skeletons, and the bones of modern quadrupeds, with those of extinct species, introduced at more early periods, and by natural causes.

Several accounts have been published within the last few years of human remains discovered in the caverns of France, and the province of Liege, which are described as being of the same antiquity with the bones of Hyænas, and other extinct quadrupeds, that accompany them. Most of these may probably admit of explanation by reference to the causes just enumerated. In the case of caverns which form the channels of subterranean rivers, or which are subject to occasional inundations, another cause of the ad-mixture of human bones, with the remains of animals of more ancient date, may be found in the movements occasioned by running water.