47o THE POPULAR SCIENCE MONTHLY 



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 be- 

 tween two visits to the Flora forest. The principal agent in disintegra- 

 tion 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 uni- 

 versity 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. 



