LIFE ON THE EARTH. 145 



now experienced in the centre of the Coal-basin of 

 Scotland, 20 higher than that of the Coal-field of 

 Michigan, and not less than 30 above that of the 

 northern part of Newfoundland, to which the American 

 Coal-basin extends. 



Again, in the Oolitic period, we find Ferns still 

 the prevalent vegetation, with gigantic Equiseta, 

 and stems and fronds of Zamioid and Cycadeoid 

 plants and Pandanacese, all indications of an equally 

 warm climate, prevalent as far north as Yorkshire 

 and Bornholm. Thus a difference of 16 or more 

 appears in favour of the ancient temperature. 



In Csenozoic Strata, the natural orders of Cucur- 

 bitacese, Anonacese, and Mpadaceae in the London 

 basin, and Palmacere in that of Paris, carry on the 

 inference to times nearer our own; but there is rea- 

 son to suspect the influence of drift like that of the 

 modern gulf-stream in transporting the numerous 

 fruits now found in the clay of Sheppey 1 . 



Coral growing into masses comparable to modern 

 reefs affords a valuable illustration of marine climate 

 at several geological epochs ; for reefs having this 

 origin, whether rising perpendicularly in the waters, 

 or accumulated under the influence of sea-currents, 

 are confined in modern nature to a limited breadth 

 on either side of the equator. The Corals which fall 



1 Bowerbank, Fossil Fruits and Seeds of Sheppey. 

 E. L. L 



