FOSSIL FLORA. 757 



determine tlie original diameter, as the bark is in no case preserved. The 

 standing trees are both conifers, and belong to the gemis Cupressinoxylon. 



Above these standing trunks many others are visilde, but the disinte- 

 grating forces of nature keep them at about the same level as that of the 

 suiTounding rock, from the fact that they tend to break up easily into small 

 fragments. Some of these trunks rise only a few inches, while otliers are 

 nearly covered by the shifting de'bris. They vary in size from 1 to 4 feet 

 in diameter, and are so perfectly preserved that the annual rings can be 

 easily counted. The internal structure is also in most cases nearly as 

 perfect as though the tree were living. The cells still retain their delicate 

 markings, and often their perfect form. 



There are numerous fossil leaves found in the rocks about the bases of 

 these trees, but none apparently corresponding to the trunks; that is, the 

 trunks are all coniferous, while the leaves are dicotyledonous; but from the 

 nature of the case a coniferous trunk is much more readil}^ pi'eserved than 

 a dicotyledonous one. 



The next forest that claims attention is the one mentioned by Mr. 

 Holmes, and is the one most frequently visited by observers. It is known 

 locally as the Fossil Forest, and is exposed on the northern slope of Amethyst 

 Mountain, opposite the mouth of Soda Butte Creek. The trunks may be 

 easily seen from the road along the Lamar Eiver and quite a mile awav. 

 They stand upright — as Holmes has said, like the pillars of some ancient 

 temple — and a closer view shows that there is a succession of these forests, 

 one above the other, through the entire 2,000 feet of this mountain. That 

 is to say, in early Tertiary time a magnificent forest ilourished in this re<jion, 

 which was buried under the debris ejected from volcanoes of greater or 

 less size that are supposed to have existed in this vicinity. The trees were 

 suiTounded by silica-charged waters and were turned to stone. The area 

 on which they grew was proliably underg(iing a very gradual submeroence 

 and the trees were slowly entombed. This is shown by the fact that the 

 trees are in an upright position and were not broken by the incomino- 

 material which covered them. 



After the first forest was entombed, quiet was restored for a sufficient 

 length of time for a second forest to grow above it. Then volcanic activity 

 was renewed, and the second forest was buried and silicified as the first had 

 been. This process was repeated until 2,000 feet of volcanic material had 



