372 JOURNAL OF THE PLYMOUTH INSTITUTION. 
this kind. This covers a mass mainly derived from oaks haying 
acorns with a long foot-stalk, and therefore termed the Peduneulated 
Oak. Below this are the relics of the Sessile Oak, so named from 
its acorns having little or no foot-stalk. Still lower are trees of a 
different kind again, amongst which the Scotch fir, Ponus sylvestris, is 
by far the most prevalent. Thanks to the Romans, we know that 
the beech held possession of Denmark 1,800 years ago; hence it 
had taken possession of the soil some time before that, and probably 
200 years may be safely allowed for this, asa minimum. As this 
tree shows no intention of giving up possession, we may add 500 
years to the foregoing figures as representing the time during 
which it would remain the characteristic Danish tree; making a 
total of 2,500 years as the chronological value of one term of the 
four which make up the bog series. The Scotch fir, the repre- 
sentative of the lowest or oldest term, does not now grow in 
Denmark, nor can even the horticulturist prevail on it to do so. 
Were we to assign 2,500 years as the mean value of each term, 
the entire bog would be worth 10,000 years. This, however, 
would be but a guess, and perhaps a rough one, of which all that 
can be said is that it is quite as likely to be below as above the 
truth. The bog, however, contains human industrial remains, 
amongst which iron tools occur; but they are found not to extend 
below the débris of the beeches. Below them are articles of 
bronze, which pass through the zone of the pedunculated oak and 
about half-way through that of the sessile variety. The lower depths 
are occupied with stone tools, all belonging to the Neolithic or 
polished kind. Steenstrup, a name which, did it need it, would 
make Denmark famous, took, with his own hands, a polished 
stone implement from beneath the prostrate trunk of a Scotch fir. 
Whatever may be the value of the Danish bogs in time, it is less 
than that separating us from the Paleolithic Age. 
The bogs are also rich in animal remains, but from top to bottom 
they are those of existing species. The peaty masses, though 
having an age to be estimated in several thousands of years, have 
failed, as we have seen, to make known to us a time so ancient as 
that of unpolished stone tools, and they equally fail to take us 
back to the era when there were on the earth any animals differ- 
ing from those which now occupy it. 
In proceeding to co-ordinate the Kent’s Hole deposits with the 
