Prof. Asa Gray on Sequoia and its History. 67 



have been the commonest coniferous tree on Disco," was 

 common in England and some other parts of Europe. So the 

 Sequoias, now remarkable for their restricted station and num- 

 bers, as well as for their extraordinary size, are of an ancient 

 stock ; their ancestors and kindred formed a large part of the 

 forests which flourished throughout the polar regions, now 

 desolate and ice-clad, and which extended into low latitudes 

 in Europe. On this continent one species at least had reached 

 to the vicinity of its present habitat before the glaciation of 

 the region. Among the fossil specimens already found in 

 California, but which our trustworthy palaeontological botanist 

 has not yet had time to examine, we may expect to find 

 evidence of the early arrival of these two redwoods upon the 

 ground Avhich they now, after much vicissitude, scantily 

 occupy. 



Differences of climate, or circumstances of migration, or 

 both, must have determined the survival of Sequoia upon the 

 Pacific, and of Taxodium upon the Atlantic coast ; and still the 

 redwoods will not stand in the east, nor could our Taxodium 

 find a congenial station in California. 



As to the remaining near relative of Sequoia^ the Chinese 

 Glyptostrohus, a species of it, and its veritable representative, 

 was contemporaneous with Sequoia and Taxodium^ not only 

 in temperate Europe, but throughout the arctic regions from 

 Greenland to Alaska. Very similar would seem to have been 

 the fate of a more familiar gymnospermous tree, the gingko 

 or Salishuria. It is now indigenous to Japan only. Its an- 

 cestor, as we may fairly call it (since, according to Heer, '^ it 

 coiTCsponds so entirely with the living species that it can 

 scarcely be separated from it'^), once inhabited Northern 

 Europe and the whole arctic region round to Alaska, and had 

 even a representative further south in our Eocky-Mountain 

 district. For some reason, this and Glyptostrohus survived 

 only on the shores of Eastern Asia. 



Lihocedrus, on the other hand, appears to have cast in its 

 lot with the Sequoias. Two species, according to Heer, were 

 with them in Spitzbergen. Of the two now living, L. decur- 

 rcns (the incense cedar) is one of the noblest associates of 

 the in-esent redwoods ; the other is far south, in the Andes of 

 Chili. 



The genealogy of the Torreyas is more obscui-e ; yet it is 

 not luilikely that the yew-like trees named Taxites, which 

 flourished with the Sequoias in the tertiary arctic forests, are 

 the remote ancestors of the three s]iecies of Torreya, now 

 severally in l^'loiida, in California, and in Japan. 



As to the pinel and firs, these were more nimierously asso- 



