96 SPENCER : THE AFFINITY OF DADOXYLON TO CORDAITES. 
in connection with Dadoxylon it will perhaps be best to begin with 
those which have been made historical by the discoveries of the late 
Mr. Witham. 
In the year 1826 a large tree trunk, 36 feet in length and 3 feet 
in diameter at the base, was discovered in the celebrated Craighleith 
Quarry, which is situated in the Calciferous Sandstone, a member of 
the Mountain Limestone series, near Edinburgh. In the year 1830 
another large tree 47 feet in length and 5 feet in diameter at the 
base, tapering to one foot seven inches at the apex, was found in the 
same quarry. The structure of the wood of these two trees appears 
to have been identical, and it was named by Lindley and Hutton 
Pinites Withami after Mr. Witham, who appears to have been the 
first to study microscopic sections of the wood of fossil plants, and to 
introduce this most interesting branch of study to the scientific 
world. The next important discovery took place the year after (1831) 
in the same quarry, when a small stem with a branch was found ; a 
thin section of the branch showed the annular rings of growth 
characteristic of the Conifers, as well as the pith, which was remark- 
able on account of its being much larger in proportion to the area of 
the woody zone than that of recent pines. The authors of the Fossil 
Flora uamed this specimen Pinites medullaris on account of its large 
pith. Two years previously a large tree trunk was found at Wide 
Open, near Newcastle, on the estate of the Rev. R. H. Brandling, in 
what Mr. Witham terms the " Grindstone Post," which was con- 
sidered to be one of the highest members of the coal formation of 
that district. The wood of this fossil tree was named by Lindley and 
Hutton Pinites Brandlingi, alter the owner of the quarry. The 
structure of the wood of all these fossil trees was regarded by 
Witham as being identical, and therefore they ought to have been 
named after the first discovered Pinites Withami. It is too late now 
to remedy the mistake, and the names are useful to denote certain 
peculiarities in the preservation of the structure and in the form of 
the pith. Thus Pinites medullaris refers to a very important charac- 
teristic feature found in all these supposed Pines, and that is the 
much larger relative proportion of the pith area than obtains in 
modern Pines ; and the structure of the wood of Pinites Brandlingi 
