nct on the inner
surface of the cranial bones. They consist of a ferruginous compound,
and, from their black colour, may be supposed to contain manganese.
Similar dendritic formations also occur, not unfrequently, on laminated
rocks, and are usually found in minute fissures and cracks. At the
meeting of the Lower Rhine Society at Bonn, on the 1st April, 1857,
Prof. Meyer stated that he had noticed in the museum of Poppelsdorf
similar dendritic crystallizations on several fossil bones of animals,
and particularly on those of 'Ursus spelaeus', but still more abundantly
and beautifully displayed on the fossil bones and teeth of 'Equus
adamiticus', 'Elephas primigenius', etc., from the caves of Bolve and
Sundwig. Faint indications of similar 'dendrites' were visible in a
Roman skull from Siegburg; whilst other ancient skulls, which had lain
for centuries in the earth, presented no trace of them. [9]

"The incipient formation of dendritic deposits, which were formerly
regarded as a sign of a truly fossil condition, is interesting. It has
even been supposed that in diluvial deposits the presence of 'dendrites'
might be regarded as affording a certain mark of distinction between
bones mixed with the diluvium at a somewhat later period and the true
diluvial relics, to which alone it was supposed that these deposits were
confined. But I have long been convinced that neither can the absence of
'dendrites' be regarded as indicative of recent age, nor their presence
as sufficient to establish the great antiquity of the objects upon which
they occur. I have myself noticed upon paper, which could scarcely
be more than a year old, dendritic deposits, which could not be
distinguished from those on fossil bones. Thus I possess a dog's
skull from the Roman colony of the neighbouring Heddersheim, 'Castrum
Hadrianum', which is in no way distinguishable from the fossil bones
from the Frankish caves; it presents the same colour, and adheres to the
tongue just as they do; so that this character also, which, at a former
meeting of German naturalists at Bonn, gave rise to amusing scenes
between Buckland and Schmerling, is no longer of any value. In disputed
cases, therefore, the condition of the bone can scarcely afford the
means for determining with certainty whether it be fossil, that is to
say, whether it belong to geological antiquity or to the historical
period.'

"As we cannot now look upon the primitive world as representing a wholly
d