Generally speaking, all adult insects have wings, and all winged insects are adults. There are exceptions to this, but they will take their places when the time comes. The young of the insects belonging to certain orders resemble their parents enough so as to be placed where they belong at a glance. This is true of the grasshoppers, katydids, and crickets, of the true bugs which include the squash-bugs, the chinch-bug, the stink-bug and others. Of most of the other orders this is not true. The young do not look at all like the adults. In many cases as, for example, the dragon fly and the mosquito, they are fitted in the immature stages to a life in the water. They must, on this account, have organs for swimming, for aquatic breathing, and for getting a living in the water. The forms of these young insects are just as varied as those of the adults, but they do not resemble the winged ones in the least. The life history collection must contain specimens of the immature forms of insect life as well as adults if it is to be most useful and complete. Some orders of insects, as for example the moths, butterflies, beetles, flies, bees, wasps, ants, and others pass through four distinct changes of form. They always follow the same order. Every generation, beginning with the egg, passes next to the larva (called caterpillar or incorrectly worm, or grub, or maggot), on to the pupa, then to the adult. The egg of an insect is often a most beautiful object. With a hand lens, which every collector will surely need, one can see its delicate colouring, its pearl-like shell, its curiously carved or sculptured surface. To get some idea of the great variety in form, colour, shape, and markings of insects' eggs, ask at your library for a book on butterflies, with coloured plates, and the chances are that you will be surprised. The second or larval stage of the insect's life is the eating, growing stage. During this stage the young bee, butterfly, ant, or moth moults several times. In this process the entire old skin is shed, an operation well worth seeing. Under the old coat a new one has formed, which being larger, accommodates itself to the insect's increased size. The larval stage is in the case of many insects the active time when, if they are vegetable feeders, they injure crops. When the larva has completed its growth it changes into a pupa. Some insects pass this third stage inside of silken cases they spin about themselves, others, after shedding the larval skin, find themselves each clad in a sort of horny coat of mail. We call these chrysalides. Some larvæ creep away into the ground, there to shed their old coats and rest inside of the pupa cases which nature provides. Each one follows the fashion of his own family and is in no danger of being mistaken for any one else.