XLIV] 



PETRIFIED TREES 



171 



this field, it is difficult to avoid a suspicion of overstraining 

 the significance of certain anatomical minutiae beyond the limits 

 of safety. 



The great abundance of petrified wood in strata ranging from 

 the late Palaeozoic through the Mesozoic and Tertiary formations, 







~ygi *jffip^!%^ii[j^-==L: 





FIG. 712. Section of the north face of Amethyst Mountain, Yellowstone Park. 



(After Holmes.) 



often in places which have yielded few other plant fossils, is in 

 itself a strong incentive to research in a department of palaeobotany 

 that has suffered from superficial work and hasty conclusions. 

 Petrified tree-trunks are among the most impressive monuments 



