Manchester Fossil Trees, and on the Formation of Coal. 2IS 



nuous or anastomosing furrows on their surface, to the swelling out at 

 the base of their stems, and to the divergence as well as the angle 

 of dip or downward direction of their roots. These characters, he 

 says, are not observable in soft monocotyledonous trees, their stems 

 never expanding laterally, and being as thick when only a few years 

 old and a foot high, as when they attain the height of 60 or 100 feet. 

 Their roots also, instead of being massive and forking, generally pre- 

 sent a dense assemblage of straight succulent fibres, like those of an 

 onion or hyacinth. Analogy, therefore, as far as outward shape and 

 habit are concerned, he adds, is strongly in favour of the fossils 

 having been solid timber trees. 



Mr. Bowman then combats the view, generally entertained, that 

 fossil stems with perpendicular furrows, as in the SigUlaria, were 

 succulent or hollow plants*. He states, that good specimens of de- 

 corticated Sigillarise exhibit fine straight, and curled or gnarled striee, 

 similar to those on the alburnum of many modern forest trees ; and 

 that tliis character, in conjunction with others, renders it almost cer- 

 tain, that the fossils had a separate bark, — a feature which is consi- 

 dered in vegetable physiology to be a proof of a woody structure. 

 He also alludes to the existence in many of the decorticated parts of 

 these fossil trees of little prominences like those in barked timber; 

 likewise to the scars left by the disarticulation of leaves ; and he ac- 

 counts for the general absence of the latter on large and old trunks, by 

 their having been obliterated, in consequence of irregular expansion 

 from the deposition of new layers of wood : he notices moreover the 

 absence in small Sigillarise of the irregular furrows observed on large 

 specimens, and due in his opinion to the unequal expansion by the 

 addition of new layers of wood. In support of these proofs of the 

 original solid nature of the trees, Mr. Bowman exhibited polished 

 slices mounted upon glass of portions of a similar fossil tree dis- 

 covered in sinking a shaft 300 or 400 yards N.W. of those found on 

 the line of the railway. The slices were made from a portion which ex- 

 hibited within the carbonized bark, a patch browner, heavier, and more 

 compact than the rest. In these slices, made under Mr. R. Brown's 

 direction, that gentleman discovered in the transverse section, the 

 uniformity of vascularity which is evidence of coniferous structure ; 

 and in the longitudinal section parallel to the medullary rays, the ex- 

 istence of these rays. The slices therefore exhibit proofs of dico- 

 tyledonous structure, and considerable probability of that structure 

 being coniferous. The important evidence however of coniferoiis 

 structure deducible from discs in sections parallel to the rays, was not 

 obtained, the vessels having apparently undergone some altera- 

 tion. 



2. With respect to the second point, that the trees grew and died 



• Specimens of recent dicotyledonous wood from New Zealand, lent to 

 tlie author by Mr. R. Brown, were exliibited on the table of the Meeting 

 Room. They displayed both ujjon the bark and the naked wood, longitu- 

 dinal ribs and intermediate furrows as regular as those on Slgillaria; ; and 

 tlitrefore prove that these characters are not incompatible with a dicotyle- 

 donous structure. 



