Jan., 1919] Effects of the Eruption on Vegetation 205 



thinner, there is abundant opportunity to observe its effect 

 on vegetation. 



Here the mud flowed down through the forest engulfing 

 the trees that stood in its path. (See below). If one 

 walks along the edge of the flow where its effect on the 

 trees can best be observed he can see what happened in the 

 clearest possible fashion. The trees and bushes everywhere 

 show evidence of disturbance by the moving stream of mud, 

 but there is no indication of such violent action as would have 

 been left in the wake of a torrent of water, for none of the trees 



Photograph by R. F. Griggs 



BURNED REMNANTS OF THE TREES ALONG THE EDGE OF THE 



MUD FLOW. 



The trees on higher ground at the right, out of reach of the mud, though killed 

 by the eruption, show no sign of fire. The mud flow, which so incinerated 

 vegetation, was entirely independent of the explosion of Katmai. (See 

 No. Ill of this series of articles). 



are uprooted or broken up by the flow. In many places the 

 tops protrude above the surface of the solidified mud. Such 

 old tops are, however, but loosely held by the mud. If one 

 takes hold of them they pull right out, when it is found that 

 they are charred through about a foot below the surface. 



The stream canyons in this district show abundant sections 

 of the mud containing such trees. The charring action was so 

 thorough that every particle of vegetation touched by the mud 



