36 MESOZOIC FLORAS OF UNITED STATES. 



alleged petrified cones of Mr. Brookbank. In passing his house, on 

 our way to Flagstaff, Mr. Brown and I were kindh' permitted by Mr. 

 Brookbank to examine all the fossils in his possession. None of the 

 supposed cones were such, and all of them belonged to the same class 

 of materials that I have described. Although thej^ are not cones, thej^ 

 have some paleobotanical interest, and I made a thorough study of 

 their origin and nature. Thej- occur in the Petrified Forest and else- 

 where, are usually spoken of Idv the inhabitants of the country as stems, 

 and are supposed to be the smaller branches belonging to the upper 

 part of the trees which make up the forest. This, however, is an 

 erroneous view, and I discovered that they always came out of the 

 interior of the trunks and belong to the bodies of the trees. They 

 vary indefinitely in size and length as well as in texture, and only a few 

 of them are surrounded by crystals. They either have to do with the 

 vascular tissues of the trunks or else they are modifications of the pitch 

 blisters described above, and represent lines along which the resin was 

 disposed to accumulate either during the growth of the tree or, more 

 probably, as a result of the process of mineralization, during which these 

 products were segregated and arranged along certain lines. I brought 

 with me a sufficient number and variety of these objects to illustrate 

 their true character. 



The petrified wood of Arizona is found widely scattered over the 

 Paleozoic terrane. One small specimen only, picked up by Mr. P. C. 

 BicknoU, was found at the foot of Red Butte, which must have come from 

 the conglomerate bed at the summit. But in the vicinitj^ of Williams, 

 both southwest and east of the town, I found many pieces of unmistakable 

 fossil wood lying about among the dark porous rocks of the lava. They 

 all show the effect of heat, are themselves somewhat porous, and have 

 doubtless lost all their minute structure, but their true nature as wood 

 can not be doubted. I brought away a number of specimens, and also 

 have those collected near Supai two j'ears before. Moreover, I met many 

 persons who reported finding it under similar conditions near Flagstaff and 

 on the north side of Mount Agassiz, as well as farther on in the direction 

 of the Grand Canyon. These occurrences are certainly difficult to explain, 

 especially in view of the fact that, with one exception, no wood has thus 

 •far been found below the true Shinarump. It seems necessary to admit 

 that not only the Moencopie beds but also the conglomerate once cov- 



