On the Formation of Coal. 175 



tained in a memoir, *' On the Vegetation of the Carboniferous 

 Period as compared with that of the present day,'' which has 

 just appeared in the last volume of the " Memoirs of the Geolo- 

 gical Survey of Great Britain ;'' and in the pages of Jame- 

 son's Edinburgh New Philosophical Journal. The author of 

 this interesting paper is Dr Hooker, botanist to the Geolo- 

 gical Survey, who, having accompanied Sir John Ross in his 

 voyage towards the South Pole, had an excellent opportunity 

 of observing vegetable life in those Antarctic regions, which 

 are usually thought to present the closest resemblance in 

 existing nature, to those conditions of climate, and of the dis- 

 tribution of land and water, which prevailed at the time when 

 the coal plants flourished in the northern hemisphere. 



It is often thought that the kind of vegetation entombed 

 in the coal formation, independent even of its amount, fur- 

 nishes strong evidence of a climate different from that now 

 existing. Dr Hooker, however, remarks, that we can never 

 hope to arrive at great precision in determining the species 

 of vegetable remains ; and that we have still less reason to 

 expect that they will prove equally appreciable indices with 

 the remains of animals, of the climate and other physical 

 features of that portion of the surface of the globe upon which 

 they formerly grew. Fossil botany has also great difficulties 

 to contend with, in the fragmentary condition of the remains 

 and in the vast extent of the existing vegetable world, which 

 must be so far mastered before any one can venture on the 

 study of the remains of ancient floras preserved in the rocks. 

 In the coal formation, however, these remains are presented 

 in vast profusion and in a great variety of states — some pre- 

 served in shales, others in ironstone, others, again, in sand- 

 stone ; some with only the outline of their external form, 

 others with their most delicate internal tissues in a condition 

 fit for microscopical examination, and thus much facilitate 

 their study. The novelty of the forms, too, whilst it adds 

 to the difficulty of the study, increases also its interest, and 

 the botanist, in descending through a few yards in the shaft 

 of a coal-pit, finds himself transported to a world far more 

 distinct from that he left above ground, than a voyage of 

 many thousand miles would produce. 



