FLORA. 229 



There are supplied details relative to indications of the 

 times at which different trees mentioned in this table and 

 allies of these had made their appearance at different 

 places, and it is added that amongst Arctic species may 

 be mentioned the following as having been the stock from 

 which have sprung the European and American plants of 

 the present day, the names of which are associated with 

 them in the following list : 



ARTIC MIOCENE FORMS. DERIVED FORMS OF THE PRESENT 



TIME. 



Potamogeton Nordenskjold, Hr... Potamogeton natans L. Europe. 



Quercus groenlandica Hr Quercus prinus L. America. 



Ulmus Braunii Hr Ulmus campestris L. Europe. 



Menyanthes arctica Hr Meny anthea trif oliata L. Europe. 



Viburnum Whymperi Hr Viburnum lantana L. Europe. 



Hedera Mac-Cluri Hr Hedera helix L. Var. hibernis. 



Europe. 



Acer otopteryx Gp Acer dasy carpum Michx. America. 



Juglans acuminata Al. Br Juglans regia L. Europe. 



Sorbus grandif olia Hr Sorbus aria L. Europe. 



Prunus staratschini Hr Prunus spinosa L. Europe. 



Crataegua oxy acauthoides Gp Crataegus oxy acantha L. Europe. 



After some other remarks in elucidation of what has 

 been advanced, Count Saporta goes on to say : ' We 

 must go about 30 degrees of latitude towards the south 

 to find, growing wild and associated in an analogous con- 

 dition, the vegetable forms which flourished then in the 

 Polar zone. The lands of that zone, at the time of which 

 a portion of their secret has now been revealed to us, 

 formed then a vast expanse, perhaps the only continent of 

 the time. These lands were at the same time affected by 

 the interior fire, exposed to incessant eruptions, and sub- 

 jected to the overflow of Basalt. It is known that such 

 a state of things is no obstacle in the way to the advance- 

 ment of vegetation, and that it even favours in some cases 

 its development in spite of the partial devastations which 

 it brings in its train. Auvergne and the Cantal in France 

 have been equally with this region, in a later age, 

 the theatre of the same phenomena ; and the abundance 

 of imprints left on the ashes and volcanic mud attest that 



