IN 1922 the Ministry of Agriculture and Fisheries issued a small publication on “Beneficial Insects”. It contained little-known information, written in a non-technical style, on those insects that are beneficial to the farmer, fruit-grower and gardener. During the sixteen years which have elapsed, this bulletin has passed through three editions and has been reprinted on five occasions. Knowledge of insects of this kind has greatly increased in the interval and the practical measures that can be taken to increase their usefulness have been extensively investigated. This new bulletin (No. 20; 1939) has been entirely re-written by Dr. W. B. Thompson and forms a useful nontechnical introduction to the subject. It is obtainable from His Majesty's Stationery Office, or through any bookseller, price 9d. net.