CARBONIFEROUS ERA. 103 



irreconcilable absurdities. The fact is, coal is a necessary 

 product of every period, and is merely the mineralised re- 

 sult of vegetable accumulation pointing rather to im- 

 mensity of time than to rapidity of growth as the cause of 

 that accumulation. It is to time, therefore, and to genial 

 equability of climate, rather than to excessive tempera- 

 ture, that we are to look for an explanation of the vegetable 

 masses of the coal period and he who would cut short the 

 difficulty by appeals to abnormal conditions, instead of ex- 

 hausting the possibilities within the scope of natural law, 

 at once does violence to Nature, and retards the progress of 

 legitimate induction. 



The vegetation to which we allude consists offucoids and 

 confervites, or sea-weeds and confervas ; of equisetites, hip- 

 purites, and asterophyUites, gigantic plants resembling the 

 horse-tails of our swamps and ditches ; of innumerable tree- 

 ferns distinguished by the forms and venation of their 

 leaves, as neuropteris (nerve-fern), cydopteris (circle-fern), 

 ylossopteris (tongue-fern), pecopteris (comb-fern), sphenop- 

 teris (w T edge-fern), and the like ; of fern stems, caulopteris; 

 of reed-like plants, calamites; of palms,* palmacites and 

 Noeggerathia ; of a vast variety of trees of unknown relation- 

 ship, as sigillaria (fluted bark), stigmaria (dotted bark), 

 now known to be the roots of sigillaria, &c., lepidodendron 

 (scaly stem), bothrodendron (pitted stem), favularia (honey- 

 combed bark), and the like ; and of true coniferous trunks 



* It has been recently questioned, and apparently on good grounds, 

 whether we have certain evidence of the existence of palms during the 

 Carboniferous epoch? The three-cornered fruits (trigonocarpum), for- 

 merly supposed to be those of palms, are now regarded as those of coni- 

 ferous plants, which, like the berry of the juniper, was enclosed in a 

 fleshy envelope ; while the broad flabelliform or fan - shaped leaves 

 (Noeygerathia) are also considered coniferous and akin to the existing 

 subtropical Salisburia. The so-called palm-stems have always been held 

 as doubtful. 



