The Origin of our British Flora 
forests of Jed and of Dalton covered huge areas in the 
south. When Robert the Bruce narrowly escaped from 
his pursuers in Glen Trool, the impression which one 
gets from the contemporary accounts is that the country 
was covered with trees, probably of pine. 
At a much earlier date one finds frequent references 
in Tacitus and other Roman writers to the Silva Cale- 
donica of, apparently, great pine trees. 
Tacitus himself is much too flowing and literary in 
his appreciation of the great Agricola for.much trust to 
be placed in his allusions, but the plain deduction from 
his and other Roman authors seems to be that Scotland 
was then a forest-clad, marshy, feverish country, which, 
in their view, would never be of the least importance to 
civilised man. 
The population seems to have been large, for it is the 
fact that the Picts and Caledonians invaded England 
before 120 A.D., about 138 A.D., in 161 A.D., on the acces- 
sion of Commodus, before 208 A.D., when Severus lost 
50,000 men in Scotland, and frequently after that. 
Moreover, there was a large population in Scotland long 
before any Roman saw the country. There were great 
Neolithic settlements which should surely have com- 
menced at least 1000 B.C. 
So far as one could draw any conclusion from these 
facts, the upper pine forest of the deposits is just the 
Silva Caledonica of the Romans and the traditional 
Scotch forest which was of pine in the uplands and of 
oak in the lowlands. 
Its destruction could be satisfactorily explained simply 
by the continual cutting and burning necessary to sup- 
port a large population, and especially by the ravages of 
goats, black cattle, and horses, which would prevent any 
reafforestation. 
So the Romans and Scotch savages would seem to 
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