Rutland.— T/ie Fall of the Leaf. 119 



this portion of the globe was at some former period more 

 elevated than at present is proved by the distribution of the 

 fauna. For example, Tierra del Fuego and Tasmania must 

 have formed integral portions of the adjacent continents, and 

 the various islands of the New Zealand Archipelago, including 

 the Chathams and Lord Howe Island, were directly or in- 

 directly connected. Still, even if we could show that the 

 evidences of ice-action now observed were due to the period of 

 elevation, it would not in any way prove that the southern 

 hemisphere has not undergone climatic changes similar to 

 those which took place in the north. There is no reason to 

 look for such a difference in the histories of the two regions ; 

 for a careful consideration will enable us to perceive that, if 

 the distribution of land and water during that time was analo- 

 gous to what it is now, the glacial cold may have been simul- 

 taneously experienced in both hemispheres, though its traces 

 cannot be readily discovered in the southern vegetation. 



For instance, were the island of South Georgia, situated in 

 a latitude corresponding with the north of Scotland, to become 

 capable of supporting vegetable life, it would require stocking 

 from entirely foreign sources. Being at present enveloped in 

 ice to sea-level, it is, of course, destitute of vegetation. A 

 flora having such an origin could afford no direct clue to the 

 former history of its region. If during the glacial period the 

 climates of the northern and southern hemispheres bore the 

 same relation to each other as at present, the condition of the 

 New Zealand Islands, supposing they existed, must have been 

 analogous to that of South Georgia. x\t most, a scanty 

 vegetation might have been found in the low lands in the 

 northern portion of the group. Under these circumstances 

 the present flora must be chiefly of recent foreign origin, and 

 we discover in it certain general characteristics that seem to 

 favour this view. For instance, the tropical nature of the 

 forest-vegetation, so frequently remarked, has been always 

 accepted as evidence of a former distribution of land which 

 enabled a more northerly flora to extend its range southward. 

 On the other hand, our open lands and mountains furnish 

 numerous species which might belong to colder climes in a 

 colder period. Nor is the presence of plant-remains allied to 

 our forest-vegetation in deposits older than the glacial period 

 necessarily opposed to the recent introduction of this portion 

 of the flora, for there is good evidence that a portion of the 

 vegetation removed by the glacial cold in Europe returned to 

 its old habitat. Thus, in an upper cretaceous deposit at 

 Aix-la-Chapelle, associated with fossil remains of Pandanacecs 

 and ProteacecB, are species of the genera Quercus and Juglans 

 now proper to that part of Europe. Though a rigorous process 

 of selection and much differentiation has taken place between 



