Some surprise was expressed in 1856, by several of the assembled naturalists at Le Puy, that the skull of the "fossil man of Denise," although contemporary with the mammoth, and coeval with the last eruptions of the Le Puy volcanoes [18], should be of the ordinary Caucasian or European type; but the observations of Professor Huxley on the Engis skull, cited in the fifth chapter, showing the near approach of that ancient cranium to the European standard, will help to remove this source of perplexity. HUMAN FOSSIL OF NATCHEZ ON THE MISSISSIPPI. I have already alluded to Dr. Dowler's attempt to calculate, in years, the antiquity of the human skeleton said to have been buried under four cypress forests in the delta of the Mississippi, near New Orleans (see above, Chapter 3). In that case no remains of extinct animals were found associated with those of Man: but in another part of the basin of the Mississippi, a human bone, accompanied by bones of Mastodon and Megalonyx, is supposed to have been washed out of a more ancient alluvial deposit. After visiting the spot in 1846, I described the geological position of the bones, and discussed their probable age, with a stronger bias, I must confess, as to the antecedent improbability of the contemporaneous entombment of Man and the mastodon than any geologist would now be justified in entertaining. [Illustration: Figure 26. Alluvial Plain of the Mississippi] (FIGURE 26. SECTION THROUGH THE ALLUVIAL PLAIN OF THE MISSISSIPPI. 1. Modern alluvium of the Mississippi. 2. Loam or loess. 3. f. Eocene. 4. Cretaceous.) In the latitude of Vicksburg, 32 degrees 50 minutes north, the broad, flat, alluvial plain of the Mississippi, a b, Figure 26, is bounded on its eastern side by a table-land d e, about 200 feet higher than the river, and extending 12 miles eastward with a gentle upward slope. This elevated platform ends abruptly at d, in a line of perpendicular cliffs or bluffs, the base of which is continually undermined by the great river.