May 1963 – vol. 56, issue 5–139 I T has always been a disputed point as to whether the Rook (Oorvus f. frugihgus) gets its bare " face " by means of abrasion of the feathers or by a moult. Most ornithologists have favoured the moult theory or have regarded it as a " natural peculiarity." This conclusion has been reached, however, by inference rather than by actual experiment. A few somewhat trivial experiments have been made with ca... This article is only available to registered users.To read more, please log in or purchase a subscription.