66 Prof. Asa Gray on Sequoia and its History. 



regions could be ascertained, my whole case would be made 

 out. The needful facts, of which I was ignorant when my 

 essay was 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 through new investigations by Heer and Lesque- 

 rcux, the results of which have been indicated to me by the 

 latter. 



The Taxodium Avhicli everywhere abounds in the miocene 

 formations in Europe, has been specifically identified, first 

 by G()e])pert, 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 

 common species ; and this has been identified by Lesquereux 

 in the miocene of the Rocky Mountains. So there is one 

 species of tree which has come down essentially unchanged 

 from tlic tertiary period, which for a long while inhabited both 

 Euro})e and North America, and also at some part of the 

 ])eriod the region which geographically connects the two (once 

 doubtless much more closely than now) , but has survived only 

 in the Atlantic United States and Mexico. 



The same Sequoia wliicli abounds in the same miocene for- 

 mations in Northern Europe has been abundantly found in 

 those of Iceland, Spitzbergen, Greenland, Mackenzie river, and 

 Alaska. It is named S. Langsdorffii^ but is ])ronounced to be 

 very much like S. sempervirens^ our living redwood of the 

 Californian coast, and to be the ancient representative of it. 

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

 been recently detected in the Rocky Mountains by Ilayden, 

 and determined by our eminent pala3ontological botanist, Les- 

 quereux ; and he assures me that he has the common redwood 

 itself from Oregon, in a deposit of tertiary age. Another 

 Sequoia {S. Sternbergn), discovered in miocene deposits in 

 Greenland, is pronounced to be the representative of S. gigan- 

 tea^ the big tree of the Californian sierra. If the Taxodium 

 of tertiary time in Europe and throughout tlie arctic regions 

 is tlie 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 red- 

 woods of California are the direct or collateral descendents of 

 the two ancient species which so closely resemble them. 



The forests of the arctic zone in tertiary times contained at 

 least three other S})ccies of Sequoia^ as determined by their re- 

 mains, one of whicli, from S])itzbergen, also much rcsendjles the 

 cunnnun redwood of California. Another, ^' which a})pears to 



