On (he Vegetation of the Carboniferous Period. 363 



class Animalia into beasts, birds, fish, reptiles, shells, &c., but much 

 study is required to attain an equal amount of acquaintance with the 

 parallel divisions of plants into exogenous, endogenous, &c. The 

 technical terms, too, employed in the one case are, very many of 

 them, universally intelligible ; whilst the majority of those applied 

 to the more conspicuous organs of plants must be acquired by a spe- 

 cial study. Lastly, the external organs of vegetables, and, espe- 

 cially such as are generally available in the fossil state, are not the 

 same guides to the affinity of the objects themselves, to their habits, 

 or to the nature of the area they occupied, which the similarly con- 

 spicuous organs of animals are. Thus, were fossil vegetables much 

 more perfect than they are, the information to be derived from 

 their study will never hold a rank of equal importance to the geolo- 

 gist with that afforded by animal remains. 



It is partly owing to these circumstances that the study has been 

 comparatively neglected, partly also because a far more comprehen- 

 sive knowledge of the existing forms of plants is required to make 

 any progress in fossil botany, than of recent zoology to advance 

 equally in palseontology ; for, whilst an acquaintance with a single 

 class of animals (the shells, for instance) enables the student to 

 understand and distinguish whole formations, he cannot, without 

 being somewhat conversant with all classes of living plants, appre- 

 ciate the value of the most perfect series of them in a fossil state. 



Turning from this discouraging view of fossil botany in general to 

 that of the particular formation to whose consideration the remainder 

 of these pages will be devoted, it is satisfactory to find that it pre- 

 sents facilities for the investioation of its vegetable remains such as 

 is afforded by no other. This is mainly due to the vast accumula- 

 tion of specimens, and to many of them being presented under very 

 different conditions in the under clay, in the shales, in nodules of 

 ironstone, and in sandstone. Had it not been for these favourable 

 circumstarices, the study of coal-fossils would have been apparently 

 hopeless ; for, whilst the clays, and ironstone, and sandstones, 

 scarcely ever contain more than one large class (ferns) in a fit state 

 for determination, the shales preserve only the outlines of another 

 (Sigillarice and Lepidodendrons^, whose affinities could hardly be 

 guessed without a microscopical examination of their hiternal tissues, 

 as these are preserved in the ironstones and sandstones. Consider- 

 ing of how exceedingly lax and compressible a tissue the coal-plants 

 were composed, it is not wonderful that instructive specimens are 

 rare ; but to appreciate to its full extent how universal is the com- 

 pression, and how complete the mutilation of almost every individual, 

 it is necessary to study the whole bed or deposit in situ. 'J'hus will 

 be seen a layer of mineralised organic matter, exceeding in bulk and 

 in ai'ea whatever any other formation may present in equal purity ; 

 for, throughout the whole mass of the coal, there will not bo found 

 one pebble, or even one grain of sand. It is a deposit of vegetable 



