Page:Popular Science Monthly Volume 83.djvu/474

470 line is seen projecting from the Lafayette a log in its original position, No stumps in situ were anywhere observed by the present writer, nor were any small branches or roots found. There are many excellently preserved knots, a beautiful example of which is seen in the picture just mentioned. So far as observed by myself, there are no other fossils in this field; but further investigation is desirable.

It is evident that disintegration is going on very rapidly in this silicified wood. The difference in the appearance of several logs was clearly noticeable after an interval of fourteen months which elapsed between two visits to the Flora forest. The principal agent in disintegration seems to be freezing; rainwater penetrates the logs and by freezing splits them. A tree which has been exposed in the writer's yard but a short while (Fig. 5) shows signs of splitting, while another in the university museum is as well preserved as when Dr. Hilgard put it there over sixty years ago.

While the Mississippi forest can not be said to rival in extent or in the coloring of its petrifactions the celebrated forests of Arizona, it is nevertheless a fine illustration of an interesting phenomenon of nature.