» J.D. Hooker, Introductory Essay to the Flora of Tasmania. 19 
very distant countries, and not of the nearest land. Thus the 
St. Helena and Ascension forms are not so characteristic of trop- 
ieal Africa as of the Cape of Good Hope. Oo ergue- 
ous peculiar N.E. American species which are not found in 
N. W. America nor elsewhere on the globe, and the Canaries 
and Azores possess American genera not found in Europe nor 
Fuegian, Andean, and European genera and species. We can- 
hot account for any of these cases of distribution between islands. 
and mountains except by assuming that the species and genera 
common to these distant localities have found their way across 
the intervening spaces under conditions which no longer exist. 
* Whilst these sheets are passing through the press, I have been informed by 
Professor Asa Gray that the flora of Japan and N.E. Asia is mach more closely 
allied to that of the Northern United States than to that of America west of the 
Rocky Mountains, 
