NORTH AMERICAN FLORA. 271 



(the curious history of which I need not rehearse) ; Sty rax of 

 cognate species ; Nyssa, the Asiatic representatives of which 

 affect a warmer region ; Gelsemiuni, which under the name 

 of Jessamine is the vernal pride of the southern Atlantic 

 States; Pyrularia and Buckleya, peculiar Santalaceous shrubs ; 

 Sassafras and Benzoins of the Laurel family; Planera and 

 Maclura ; Pachysandra of the Box tribe; the great develop- 

 ment of the Juf/landacece (of which the sole representative 

 in Europe probably was brought by man into southeastern 

 Europe in pre-historic times) ; our Hemlock ^nruces, Arbor- 

 Vitae, Chama3cyparis, Taxodium, and Torrey, 7. Q ggj heir east 

 Asian counterparts, the Roxburgliiacecv, represented by 

 Croomia, — and I might much further extend and particularize 

 the enumeration, — you will have enough to make it clear that 

 the peculiarities of the one flora are the peculiarities of the 

 other, and that the two are in striking contrast with the flora 

 of Europe. 



This contrast is susceptible of explanation. I have ven- 

 tured to regard the two antipodal floras thus compared as the 

 favored heirs of the ante-glacial high-northern flora, or rather 

 as the heirs who have retained most of their inheritance. 

 For, inasmuch as the present arctic flora is essentially the 

 same round the world, and the Tertiary fossil plants entombed 

 in the strata beneath are also largely identical in all the longi- 

 tudes, we may well infer that the ancestors of the present 

 northern temperate plants were as widely distributed through- 

 out their northern home. In their enforced migration south- 

 ward, geographical configuration and climatic differences 

 would begin to operate. Perhaps the way into Europe was 

 less open than into the lower latitudes of America and eastern 

 Asia, although there is reason to think that Greenland was 

 joined to Scandinavia. However that be, we know that Europe 

 was fairly well furnished with many of the vegetable types 

 that are now absent, possibly with most of them. Those that 

 have been recognized are mainly trees and shrubs, which 

 somehow take most readily to fossilization, but the herbaceous 

 vegetation probably accompanied the arboreal. At any rate, 

 Europe then possessed Torreyas, and Gingkos, Taxodium and 



