WARD.] PETRIFIED FORESTS OF ARIZONA. 331 
to their positions. In all that came under my observation I failed to find any evi- 
dence that they had grown in the vicinity. All the trunks are stripped of their 
branches and exhibit precisely the appearance of those transported to some distance 
by the agency of water. In confirmation of this view I should also say I found in 
the marls, with the entire trunks, rounded and water-worn fragments of wood, in 
some instances silicified and in others converted into lignite. 
I gathered the same impression from all the collections of silicified wood which I 
observed in this formation in western New Mexico, viz, that all had been trans- 
ported, but not far removed from their place of growth. 
Although it is easy to find petrified limbs and small twigs among 
the other objects, still these occur sporadically and accidentally at any 
and all points. They are no more likely to be found beyond the termi- 
nation of the tall trunks than anywhere else, as would be the case if the 
trees lay near where they grew. In fact, it happened that I never 
found small twigs in this position, although I searched in hundreds of 
cases. I found no petrified cones, but I heard vague reports of their 
having been found. It would be strange if none were preserved in 
such a vast mass of trunks of cone-bearing trees. 
Finally, the great abundance of the material would seeni to negative 
the idea that it could have all grown on the same area. Even if every 
tree had been preserved, there are places where it would have been 
impossible for them to stand as thickly as they lie on the surface, not 
to speak of the space that trees in a forest require in order to thrive, 
as these trees evidently did thrive. And while there is now no place 
where they lie so thickly in the original bed of sandstone, still, even 
here they are’ not only all prostrate, but lie in little collections and 
huddles, quite differently from what should be expected if they were 
precisely where they grew. 
The preservation of a forest in situ with the trunks erect could 
scarcely take place except by some sudden, commonly eruptive agency. 
Such agencies have undoubtedly operated in the preservation of the 
petrified forests of the Yellowstone Park, and of others that I have 
visited in Wyoming and elsewhere, in which the stumps and some- 
times tall trunks do stand in position with their roots in the ground, 
but in the region under consideration there are only faint indications 
of eruptive agencies, certainly not sufficient to account for the 
phenomena. 
The indications, therefore, all point to some degree of transporta- 
tion of this material by water antecedent to petrifaction, and the great 
amount of it at this particular place argues for the existence there of 
such a condition as would arrest the process and cause the floating 
logs to accumulate in masses, as often happens in great eddies or the 
deltas of rivers. The character of the bed in which they occur further 
supports this view. The coarse sand and gravel, highly favorable to 
the process of silicification, denotes the proximity of the land, and the 
