S86 • M. Brongniart's OhserDatio7is mi some 



If all the proofs which we have adduced establish almost with 

 certainty the resemblance of these immense stems to the stems 

 of the arborescent ferns, a very remarkable character distin- 

 guishes, if not all the Sigillariae, at least some of them, from our 

 presently existing arborescent ferns. All the tree ferns known 

 present a perfectly simple stem, similar in its general form to 

 that of the palms, cycases, &c., but commonly broader toward 

 the base : a character which is not observed in the stems of the 

 greater number of arborescent monocotyledoncs, and which is 

 equally observed in the fossils of the genus Sigillaria. All the 

 specimens of these fossils which I had hitherto observed in col- 

 lections were perfectly simple, and this character appeared to be 

 common to all the species of the genus. In conjunction with 

 several others it had served to distinguish this genus from the 

 Sagenaria3, the stem of which is commonly dichotomous. This 

 difference would tend to confirm the analogy of the former of 

 these genera with the ferns, and of the latter with the Lycopo- 

 dia, I was therefore very much astonished on seeing, in the 

 collection of M. de Derschau, engineer of mines of the Grand 

 Duchy of the Lower Rhine, a stem which was indicated by all 

 these characters to belong to the Sigillarite, and which was yet 

 twice divided into two. Three specimens of the same species pre- 

 sented this character more or less completely. Having myself 

 descended into one of the coal mines of the neighbourhood 

 of Essen (the mine of Kunzwerk), I was enabled to satisfy 

 myself on the spot regarding this remarkable organization. 

 The almost vertical roof of one of the beds of coal, in which the 

 gallery had been wrought, presented an immense quantity of 

 impressions of vegetables of different species. After having 

 seen with astonishment, among the remains of this ancient fo- 

 rest, stems of Sagenariae of nearly two feet diameter rising per- 

 pendicularly from the bottom of the gallery, dividing once or 

 twice, and presently losing themselves in the rocks which cover- 

 ed this gallery, without its being possible to judge whether 

 their length was proportional to their diameter ; after having 

 endeavoured in vain to trace several of these stems, which were 

 interwoven in all directions, I at length came upon a stem of 

 Sigillaria, the position of which enabled me to trace it in almost 

 its whole extent. This stem lay parallel to the bottom of the 



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