334 GREAT BRITAIN WITH A TROPICAL CLIMATE. 



surface. But even assuming that there may have been 

 varieties of these animals which inhabited colder 

 countries, all doubt as to the prevalence of a tropical 

 climate in Great Britain, at an earlier era, is set at 

 rest, by the finding of innumerable tropical ferns, 

 palm leaves, and other remains of heat-loving plants, 

 in the coal measures of the great Northern coal 

 field. This makes good what we have said about 

 vegetation being conclusive as to the climate of a 

 country. 



Reverting, however, to the question respecting the 

 animals, stated on the high authority of Emin Pasha to 

 have descended to our times as relicts from a vast 

 antiquity everywhere, as Mr. Wallace observes, the 

 animals which have most recently become extinct, 

 resemble more or less closely those now living in the 

 same country.* Now, in the case of the giraffe or 

 camelopard, we have an animal unique in type, all 

 its congeners having passed away. The same may be 

 said with reference to the hippopotamus. Neither 

 resemble any other species of animals at present surviving 

 in the African continent, or elsewhere. 



These animals, in fact, are so entirely different from 

 any of the quadrupeds at present existing in any other 

 part of the world, that they represent to us, what 

 undoubtedly seem to be the surviving types of a past 

 age, when the earth was peopled with the extinct 

 monsters of primeval times. Among these, numerous 

 species of elephants and rhinoceri are known to have 

 existed ; of these the Mammoth (Elephas Primogenius) 

 and the Mastodon (Mastodon Var., Sp.) were probably 

 the most prominent representatives. They were im- 



* See Island Life, by Alfred R. Wallace, 1880, p. 100. 



