Note 11 — PART II. BRITISH FOREST TREES USED AS NAVAL TIMBER.

In those we observed, we considered this last circumstance had a considerable share as a predisposing cause of the attack of the worm. Forests of Pinus sylvestris are sometimes destroyed by insects under the bark, in cases where it is difficult to decide whether external circumstances, such as a dry warm season, has been promotive of the increase of the insect itself, or has induced some disorder in the plant, rendering the juices more suitable aliment to the worm.