~Observe.~--The shape of the various kinds of cases; the materials, and how fastened together (chiefly by silk); the part of the larva that protrudes from the case; the movement, and how caused; the fitness of the case as a protection. Note hardness, colour, and shape as protective features. The pupils will be fortunate if they observe the sudden rise of the larva to the surface of the water and the almost instantaneous change into the four-winged fly. INSECTS SUITABLE FOR LESSONS IN FORM II Walking-stick insect, katydid, cricket, mole-cricket, clothes-moth, giant water-bug, potato beetle, click-beetle, luna moth, and swallow-tail butterfly. CHAPTER IX FORM III AUTUMN GARDEN WORK The pupils in this Form should be able to do all of the work required of them in the garden without assistance. They should aim at intensive and thorough cultivation and, in the autumn, when the plants of their gardens ripen, these should be removed and the soil carefully spaded. They should continue the work of selecting the seed from the best flowers, as indicated in the work for Form II, and should grow some seed from vegetables and perennials seen to be particularly good. Boys in this Form may also wish to do some gardening for profit. In some cases where there is plenty of space, this may be carried on in a part of the school garden set aside for that purpose. Usually, however, it will be found most convenient to carry it on in the home garden. Best varieties for local markets should then be grown and attention given to the proper time and manner of marketing or storing for a later market. Cool, well-ventilated cellars are best for most fruits and vegetables. TREATMENT OF FUNGI During the summer and early autumn months attention should be given to the spraying of plants for blight and for injurious insects. The potato is commonly affected by a fungous disease which causes the stalks to blacken and die before the tubers have matured. This disease may be prevented in large measure by the use of a fungicide known as Bordeaux mixture. This may be prepared as follows: