224 ESS A YS. 



lock Spruce, Arbor-Vitae, Taxoclium, or Torreya. As com- 

 pared with northeastern Asia, Europe wants most of these 

 same types, also the Ailantus, Gingko, and a goodly number 

 of coniferous genera. I cannot point to any types tending 

 to make up the deficiency, that is, to any not either in east 

 North America or in northeast Asia, or in both. Cedrus, 

 the true Cedar, which comes near to it, is only north African 

 and Asian. I need not say that Europe has uo Sequoia, and 

 shares no special type with California. 



Now the capital fact is, that many and perhaps almost all 

 of these genera of trees were well represented in Europe 

 throughout the later Tertiary times. It had not only the 

 same generic types, but in some cases even the same species, 

 or what must ])ass as such, in the lack of recognizable distinc- 

 tions between fossil remains and living analogues. Probably 

 the European Miocene forest was about as rich and various as 

 is ours of the present day, and very like it. The Glacial pe- 

 riod came and passed, and these t}^pes have not survived there, 

 nor returned. Hence the comparative poverty of the existing 

 European sylva, or, at least, the probable explanation of the 

 absence of those kinds of trees which make the characteristic 

 difference. 



Why did these trees perish out of Europe but survive in 

 America and Asia ? Before w r e inquire how Europe lost them, 

 it may be well to ask, how it got them. How came these 

 American trees to be in Europe ? And among the rest, how 

 came Europe to have Sequoias, now represented only by our 

 two Big Trees of California ? It actually possessed two species 

 and more ; one so closely answering to the Redwood of the coast 

 ranges, and another so very like the Sequoia gigantea of the 

 Sierra Nevada, that, if such fossil twigs with leaves and cones 

 had been exhumed in California instead of in Europe, it would 

 confidently be affirmed that we had resurrected the veritable 

 ancestors of our two giant trees. Indeed, so it may probably 

 be. " Caelum non animam mutant," etc., may be applicable 

 even to such wide wanderings and such vast intervals of time. 

 If the specific essence has not changed, and even if it has suf- 

 fered some change, genealogical connection is to be inferred 

 in all such cases. , 



