426 Barry: Sylvan Vegetation of Fylingdales. 
or sway in the breeze. Large flocks of Jackdaws and Starlings 
invariably pay their attention to the caterpillars; and, indeed, 
generally give one the first notice of the plague having begun. 
The effect, however, produced by them in the main woods is 
quite insignificant. Near the house, on the other hand, where 
Oaks are intermixed with other trees, and where birds of all 
kinds are constantly present, but little damage is, as a rule, 
to be perceived. 
The years in which the Oaks escape the enemy seem to be: 
(1) Those in which there are heavy and constant falls of rain 
during the caterpillers season. (2) Early years, when the leaf 
gets a start of the caterpillar, and hardens. At any rate, it 
is noticeable that in the plague years those Oaks which are 
exceptionally forward are immune; whilst in plague-free, or 
nearly plague-free, years the late-leafing trees, as those on 
the north edges of the woods, are attacked. 
INDIGENOUS TREES OF THE SECOND CLASS. 
The Birch (Betula verrucosa Ehrh.) takes a subordinate 
position in this Dale as compared with that taken by it in other 
dales of Yorkshire. With the exception of a few scattered 
standards, and these chiefly near the moor edge, the only 
woods, or remains of woods, of birch are in the Derwent 
section of the township. 
As to the causes of this feature, no doubt some part has 
been played by man. In the main dale, which has always been 
the centre of population, and must always have been more 
under the woodman’s eye, Birch may possibly have been largely 
cut out in mixed woods, in order to make room for more 
valuable timber, and not being a species which is tolerant of 
shade, has failed to reappear, as other trees would have done. 
At the same time, I think that there may have been natural 
causes as well. And I should be inclined to specify under this 
head :—(1) A soil unsuited to the Birch in the cold, stiff glacial 
clay, which fills the ravines and much of the hillsides in the area 
last noticed. (2) Exposure to sea winds. 
In regard to the latter circumstance, my attention was first 
drawn to it by losses after planting in such situations. Indeed, 
after the sudden loss, about eighteen years ago, of nearly all 
the then-to thriving Birch in a mixed plantation, some ten 
years of age, and some three acres in extent, which was on a 
steep slope, with a loamy soil, but exposed to the east and 
north-east, I was careful not to plant this species of tree 
Naturalist, 
