NORTH AMERICAN FLORA. 271 
(the curious history of which I need not rehearse) ; Styrax of 
cognate species; Nyssa, the Asiatic representatives of which 
affect a warmer region; Gelsemium, which under the name 
of Jessamine is the vernal pride of the southern Atlantic 
States; Pyrularia and Buckleya, peculiar Santalaceous shrubs 3 
Sassafras and Benzoins of the Laurel family; Planera and 
Maclura; Pachysandra of the Box tribe; the great develop- 
ment of the Juglandacee (of which the sole representative 
in Europe probably was brought by man into southeastern 
Europe in pre-historic times) ; our Hemlock Spruces, Arbor- 
Vite, Chamecyparis, Taxodium, and Torreya, with their east 
Asian counterparts, the Loxburghiacew, 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 
