WESEL AND WEBEE. BROWN-COAL FLORA. 7 



tinize very closely the evidence on which we are expected to be- 

 lieve that species of Protea and of BanJcsia formerly flourished in 

 one and the same district. 



Moreover, these supposed Proteacece are found associated in. this 

 tertiary deposit with a remarkable abundance of Cupuliferce ; 

 whereas, in the present state of the earth, the countries which 

 chiefly abound with Proteacece (South Africa and the continent of 

 Australia) are entirely destitute of Cupuliferce. 



Still, we must not push this argument too far, nor too hastily and 

 positively reject the evidence for the co- existence, in a former 

 state of things, of groups of plants which our present knowledge 

 leads us to regard as belonging to distinct and separate regions. 

 Our knowledge of botanical geography is still too incomplete to 

 authorize us to say positively that such and such genera or families 

 of plants cannot occur in company. Recent discoveries have given 

 several cautions against too absolute a dogmatism on such points. 

 Not very long ago, it would have been thought most improbable 

 that numerous species of RJiodoclendron should be found in the 

 Island of Borneo, almost under the equator. Yet such is ascertained 

 to be the fact ; and on the same mountain with these Rhododendrons, 

 and with species of Nepenthes and other especially tropical genera, 

 has been found a new species* of a very peculiar genus of Coniferce 

 (Phyllocladus), otherwise confined to Tasmania and New Zealand ; 

 and another plant belonging to a genus (Drimys) of which the previ- 

 ously known species were shared between South America and New 

 Zealand. The fact pointed out by Dr. Hooker f, of a species of Eose 

 growing wild abundantly in the tropical plains of Bengal, is an- 

 other striking exceptional instance. The vegetation of the Kliasia 

 Mountains, so well described by the same great botanist, seems to 

 present some analogy to the curious mixture of forms characteristic 

 of the Brown- coal flora ; in particular, one or more well characterized 

 Proteacece (Helicia) grow there in company with numerous Oaks. 

 We must remember, too, it is possible that the plants of the Ehenish 

 Brown -coal may not all have grown at the same elevation ; some 

 may have been brought down by rivers or floods from higher 

 districts. 



On the whole, we may probably conclude, with some confidence, 

 that this Brown-coal flora indicates a climate considerably warmer 

 than that now prevailing in Middle Europe, yet not absolutely 

 tropical. 



The number of species of Perns in this list (five) is small in 

 proportion to the tol^al number of plants, being not quite 1 : 47. A 

 small proportional number of Ferns seems characteristic of most of 

 the tertiary floras hitherto described ; probably there was something 

 in the natux'e of the localities where these deposits were formed, 

 unfavourable to this family of plants. 



Mosses are so rare in a fossil state, that the occurrence of a single 

 well-marked Moss in the deposit in question is interesting. 



* ' Himalayan Journals', vol. ii. 



t See Sir W. Hooker's ' Icones Plantarum', vol. ix. 



