MANY useful reviews are contained within the pages of vol. 5 of the Horticultural Education Association's yearbook for 1937 "Scientific Horticulture" (Pp. 196+xxxii, 3s. 6d. net, from the Hon. Editor, S. E. Agric. Coll., Wye, Kent), which constitute a welcome channel for the distribution of knowledge from the research worker to the teacher of horticulture. "Some Recent American Work on the Copper Fungicides" is described by Mr. R. W. Marsh ; Prof. Stoughton contributes "A Review of the Problem of Bud Dormancy". Dr. O. N. Purvis discusses recent Dutch research on the temperature requirements of hyacinths, and Dr. Meirion Thomas has a paper on "Plant Hormones and Their Possible Importance in Horticulture". Dr. F. Kidd and Dr. G. West show that apples destined for long-period gas storage should be picked within a fortnight of the 'climacteric phase'. This is the time when growth in size of the apple ceases in autumn, and is indicated in practice when the fruit can just be detached by gently twisting it on its stalk. The late Dr. W. Maldwyn Davies describes the results of his experiments on factors which affect the distribution of virus-transmitting aphids, particularly Myzus persicce. Winged individuals of this species fly readily when the temperature reaches 65° F. Increasing humidity deters the movement of winged aphids, and flight ceases completely when the wind velocity rises above four miles per hour. Dr. T. Whitehead has correlated this knowledge with a survey of districts in North Wales which are suitable for the growth of virus-free seed potatoes.