The destruction of oak by the death-watch beetle.

CERTAIN of the oak timbers of Rothamsted House were recently found to be extensively damaged by wood-boring insects, the damage being ascribed chiefly to the death-watch beetle (Xestobium rufovillosum).' The timbers are believed to be of great age, and some were probably used in an earlier building. In 1623 the house was extensively altered and the exposed timbering of the original house covered by a brick front, which prevented the damage from being observed before. It is certain, therefore, that the structural timbers are more than 300 years old and probably considerably older. Some of the framing posts supporting the principal rooms were in a serious condition as a result of Xestobium attack and had to be replaced. The opportunity was taken of obtaining analyses of this wood and of the borings or frass to which much of the wood had been reduced. In this way some additional information as to the wood constituents utilized by these larvae has been obtained.