Swaine and Craighead (1924) have presented evidence that outbreaks of the spruce budworm occurred in Eastern Canada in 1806 and in 1878. In those days the wood supply appeared to be unlimited and the forest represented, to some extent, an obstacle that had to be removed so that the land could be cultivated. Balsam fir, the tree principally affected by the budworm, was seldom used for lumber when spruce was available. It can hardly be considered, therefore, that these early outbreaks caused much direct economic loss. If the trees had not been killed by the budworm, over-maturity and related factors would have removed them to make way for a new stand. In fact, were it not for the undesirable effects of budworm outbreaks on subsequent forest composition, it might even be argued that they were beneficial under certain conditions.