26 Fossil Wood from Macquarie Plains . 
together in such close approximation that the microscope 
does not detect an interstice, though the least force se¬ 
parates them. 
From the appearance of the fossil, its coniferous 
structure is almost self-evident. But to prove that it was 
a pine wood, as nearly as our present knowledge of Fossil 
Botany will admit of, it is necessary to examine so thin a 
slice that the nature of the woody fibre may be micro¬ 
scopically observed by transmitted light: such slices 
have hitherto only been prepared by the most skilful 
lapidary, and at a great cost. In this iustance the wood is 
already separated into lamellae admirably adapted for 
this purpose, and far more beautifully than could possibly 
be effected by hand. Under these circumstances, with 
a good microscope, each of these fibres is seen to bear 
the distinctive character of a pine wood, being marked 
with a series of discs considered as glands, and which 
constitute the glandular woody tissue. 
The nature of these discs is still perhaps disputable, 
and is not immediately connected with the present subject. 
Such a structure is nearly confined to the Conifercc , and 
is essential to them, so far as we at present know. 
Hence it is almost certain that the present fossil 
belonged to trees of an order whose different species 
never grow separately, but cover immense tracts of land 
with often a gigantic vegetation. 
How the silicification was effected without there exist¬ 
ing a bond of union between the separate fibres, is a most 
interesting question; and further, the nature of the 
cleavage of the fossil, some other circumstances con¬ 
nected with it, and the ease with which it can be ex¬ 
amined, may be expected to add much to what is already 
known of the physiology of trees, their growth and 
development. 
