OF LOWER GREENSAND PLANTS. 77 



further investigated by Lingelsheim (1908), who found that 

 it did not hold in all cases in the living American varieties 

 he examined. 



The likelihood that some of the species of wood now described 

 belong to Sequoia, is illustrated by the reverse case, where 

 Knowlton (1899 B) identifies one of the large fossil tree-trunks 

 from the Yellowstone Park as Sequoia magnijica without any hesi- 

 tation, though the pitting of the ray-cells, for instance, cannot be 

 seen in the fossil. He says : u The dimensions of the various 

 elements are much the same in the living and fossil specimens, 

 thus leaving no doubt as to their close affinity." Such data, 

 recent work has shown, afford no clue to true affinity ; and I 

 should hesitate to do more than term Knowlton's plant Cupres- 

 sinoxylon sp. or some nou-committal species. The fine photo- 

 graph of the transverse section of the wood, while it is very 

 similar to that of the living Sequoia, might equally be taken 

 from any of half the known species of Conifers. Jeffrey (1908, 

 p. 600) says that " the wood of early Cretaceous Pines had not 

 yet acquired the marginal tracheids which are found in those 

 of late Cretaceous and later epochs." The wide-reaching con- 

 clusions in this paper, which Prof. Jeffrey deduces from this 

 misconception, may be summed up in his own words : " tho 

 Taxodineae and Cupressinea? did not exist before the very end of 

 the Cretaceous or, more probably, before the beginning of the 

 Tertiary." 



Cones of Sequoia have not been found in the Lower Green- 

 sand deposit, but from the French Portlandian undoubted cones 

 are described, so that the want of cones in our deposits is 

 probably a local accident (see Fliche & Zciller, 1905). 



The interest of the foliage of Sequoia just described lies in the 

 fact that, as its internal anatomy is so well petrified, its 

 identification is based on a sure foundation, and it suffices to 

 prove the existence of Sequoia long before the Tertiary period ; 

 though Jeffrey (1908) endeavoured to demonstrate that all 

 the early fossils referred by Zeiller and others to Sequoia were 

 Araucarians, and that Sequoia did not appear till Tertiary 

 times. 



The new Sequoia is the only species, so far as I am aware, in 

 which the internal anatomy of the leaf is petrified. 



