ON THE DERIVATION OF AMERICAN PLANTS. 731 



published, have now been for some years made known, thanks mainly 

 to the researches of Heer upon ample collections of arctic fossil plants. 

 These are confirmed and extended by new investigations, the results 

 of which have been indicated to me by the latter. The taxodium, 

 which everywhere abounds in the Miocene formations in Europe, has 

 been specifically identified, first by Goeppert, then by Heer, with our 

 common cypress of the Southern States. It has been found, fossil in 

 Spitzbergen, Greenland, and Alaska, in the latter country along with 

 the remains of another form, distinguishable, but very like the com- 

 mon species ; and this has been identified by Lesquereux in the Mio- 

 cene of the Rocky Mountains. So there is one species of tree which 

 has come down essentially unchanged from the Tertiary period, which 

 for a long while inhabited both Europe and North America, and also 

 at some part of the period the region which geographically connects 

 the two (once doubtless much more closely than now), but survives 

 only in the Atlantic United States and Mexico. The same Sequoia 

 which abound in the same Miocene formations in North Europe has 

 been now abundantly found in those of Iceland, Spitzbergen, Green- 

 land, Mackenzie River, and Alaska. It is named Sequoia langsdupii, 

 but is pronounced to be very much like Sequoia sempervirens, our 

 living redwood of the Californian coast to be the ancient representa- 

 tive of it. Fossil specimens of a similar, if not the same, species have 

 been recently detected in the Rocky Mountains by Hayden, and de- 

 termined by our eminent paleontological botanist, Lesquereux, and he 

 assures me that he has the common redwood itself from Oregon, in a 

 deposit of Tertiary age. Another Sequoia {Sequoia stembergii), dis- 

 covered in Miocene deposits in Greenland, is pronounced to be the 

 representative of Sequoia giga?itea, the big tree of Californian sierra. 

 If the taxodium of the Tertiary time in Europe and throughout the 

 arctic regions is the ancestor of our present bald cypress, which is 

 assumed in regarding them as specifically identical, then I think we 

 may with our present light fairly assume that the two redwoods of 

 California are the probable descendants of the two ancient species 

 w r hich so closely resemble them. The forests of the arctic zone in 

 Tertiary times contained at least three other species of Sequoia, as 

 determined by their remains, one of which, from Spitzbergen, also 

 much resembles the common redwood of California. Another, " which 

 appears to have been the commonest coniferous tree on Disco," was 

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

 as, now remarkable for their restricted station and numbers, 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 desolated 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 



