162 ESSAYS. 



Gilead-tree ; more Beeches than there are now, a Hornbeam, 

 and a Hop-Hornbeam, some Birches, a Persimmon, and a 

 Planer-tree, near representatives of those of the Old World, 

 at least of Asia, as well as of Atlantic North America, but 

 all wanting in California ; one Juglans like the Walnut of 

 the Old World, and another like our Black Walnut ; two or 

 three Grapevines, one near our southern Fox Grape or Mus- 

 cadine, another near our northern Frost Grape ; a Tilia, very- 

 like our Basswood of the Atlantic States only : a Liquidam- 

 bar ; a Magnolia, which recalls our M. grandiflora ; a Lirio- 

 dendron, sole representative of our Tulip-tree ; and a Sassa- 

 fras, very like the living tree. 



Most of these, it will be noticed, have their nearest or their 

 only living representatives in the Atlantic States, and when 

 elsewhere, mainly in eastern Asia. Several of them, or of 

 species like them, have been detected in our tertiary deposits, 

 west of the Mississippi, by Newberry and Lesquereux. Her- 

 baceous plants, as it happens, are rarely preserved in a fossil 

 state, else they would probably supply additional testimony 

 to the antiquity of our existing vegetation, its wide diffusion 

 over the northern and now frigid zone, and its enforced mi- 

 gration under changes of climate. 1 



Concluding, then, as we must, that our existing vegetation 

 is a continuation of that of the tertiary period, may we sup- 

 pose that it absolutely originated then ? Evident!}' not. The 

 preceding cretaceous period has furnished to Carruthers in 

 Europe a fossil fruit like that of the Sequoia gigantea of the 

 famous groves, associated with Pines of the same character as 

 those that accompany the present tree ; has furnished to Heer, 



1 There is at least one instance so opportune to the present argument 

 that it should not pass unnoticed, although I had overlooked the record 

 until now. Onoclea sensibilis is a Fern peculiar to the Atlantic United 

 States (where it is common and widespread) and to Japan. Professor 

 Newberry identified it several years ago in a collection obtained by Dr. 

 Hayden of miocene fossil plants of Dacota Territory, which is far be- 

 yond its present habitat. He moreover regards it as probably identical 

 with a fossil specimen " described by the late Professor E. Forbes, under 

 the name of Filicites Hebridicus, and obtained by the Duke of Argyll from 

 the Island of Mull." 



