273 
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 Sigillaria, were 
succulent or hollow plants*. He states, that good specimens of de- 
corticated Sigillariz exhibit fine straight, and curled or gnarled striz, 
similar to those on the alburnum of many modern forest trees ; and 
that this character, in conjunction with others, renders it almost cer- 
tain, that the fossils had a separate back,—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 
their 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 Sigillarize 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 coniferous 
structure deducible from discs in sections parallel to the rays, was not 
obtained, the vessels having apparently undergone some alteration. 
2. With respect to the second point, that the trees grew and died 
on the spots where they are now found, and that they were not drifted 
from distant lands, Mr. Bowman says, the arguments in favour of 
the formation of beds of coal by a series of subsidences of the sur- 
face on which the vegetables that produced the coal grew, naturally 
lead to the inference that the trees associated with the coal also 
flourished on the same spots. In opposition to the opinion that trees 
would naturally float in an upright position in consequence of the 
greater specific gravity of the base and roots, he asserts, that the 
* Specimens of recent dicotyledonous wood from New Zealand, lent to 
the author by Mr. R. Brown, were exhibited on the table of the Meeting 
Room. They displayed both upon the bark and the naked wood, longitu- 
dinal ribs and intermediate furrows as regular as those on Sigillariz ; and 
therefore prove that these characters are not incompatible with a dicotyle- 
donous structure. 
