Six,—After reading Prof. Julian Huxley's interesting article on " Holiday Birds " I recalled what was to me a curious and unusual performance on the part of rooks. Hearing a great and excitable cawing of rooks in the sky over a neighbouring field, I looked up to see a colony of them in flight chased by one lone rook some little distance behind. Having chased the marauders away. I noticed the pursuer return to a tree on which, to my surprise, I saw another colony of rooks to which evidently the valiant bird belonged.
I concluded that one colony had trespassed upon the domain of the other, and that the mode of attack among rooks must be for the General to take the field while the Army looks on, and holds itself in reserve in case of need. I wonder is this a usual sight or no, and how it is to be explained.—Yours, G. HUMPHREY EVANS. Llanfihangel-Gobion, Near Abergavenny.