THE FLORA OF THE EARLY MESOZOIC. 



187 



taceous, however remarkable we may think it that in that 

 period it should have developed into so many species ; and 

 it is still more surprising that two species already make 

 their appearance which approach so near to the living 

 Sequoia sempervirens and 8. gigantea. 



Altogether, we have become acquainted, up to the 

 present time, with twenty-six species of Sequoia. Four- 

 teen of these species are found in the Arctic zone, and 

 have been described and figured in the "Fossil Flora 

 of the Arctic Kegions." Sequoia has been recognised by 

 Ettingshausen even in Australia, but there in the Eocene. 



This is, perhaps, the most remarkable record in the 

 whole history of vegetation. The Sequoias are the giants 

 of the conifers, the grandest representatives of the family, 

 and the fact that, after spreading over the whole northern 

 hemisphere and attaining to more than twenty specific 

 forms, their decaying remnant should now be confined to 

 one limited region in western America and to two species 

 constitutes a sad memento of departed greatness.* The 

 small remnant of 8. gigantea still, however, towers above 

 all competitors, as eminently the "big trees " ; but, had 

 they and the allied species failed to escape the Tertiary 

 continental submergences and the disasters of the glacial 

 period, this grand genus would have been to us an extinct 

 type. In like manner the survival of the single gingko 

 of eastern Asia alone enables us to understand that 

 great series of taxine trees with fern-like leaves of which 

 it is the sole representative. 



Besides these peculiar and now rare forms, we have in 

 the Mesozoic many others related closely to existing yews, 

 cypresses, pines, and spruces, so that the conifers were 

 probably in greater abundance and variety than they are 

 at this day. 



* The writer has shown that much of the material of the great lignite 

 beds of the Canadian Northwest consists of wood of Sequoia of both the 

 modern types. 



