THE gall midges or Cecidomyidse are a family of rather primitive, structurally degenerate Diptera, of very small or minute size. They derive their name from the fact that the majority of species during their larval stages are plant-feeders which induce in their hosts the malformations termed galls or cecidia. But the family contains many more generalized species which live on fungi or in decaying plant material; and a few are carnivorous, preying upon scale insects, mites, white-flies, other gall midges and the like, letting the blood of their victims so neatly that an aphid may be bled to death without perceiving the attack. Gall Midges of Economic Importance By Dr. H. F. Barnes. (Agricultural and Horticultural Handbooks.) Vol. 1: Gall Midges of Root and Vegetable Crops. Pp. 104 + 10 plates. 12s. 6d. net. Vol. 2 Gall Midges of Fodder Crops. Pp. 160 + 4 plates. 15s. net. (London: Crosby Lockwood and Son, Ltd., 1946.)