At the very extremity of the abdomen the female has two pairs of horny valves or hooks, each pair placed back to back with their points directed outwards, and arranged so that all four hooks can be brought with their points close together. By this means a sharp pointed lever is formed which can be turned around, evolved, and forked. With this apparatus she drills a small hole and by means of a series of muscular efforts and the continuing opening and closing of the valves provided with the formation of the abdomen, she actually bores to a depth of 6 to 7 centimetres, or about 3 inches. Here she deposits her eggs--normally about eighty--regularly arranged in a long cylindrical mass and envelopes them in a spumous or sort of glutinous secretion, so that the whole are quite tapped up and level with the surface of the ground. This substance when dried is more or less impassable and affords protection to the eggs from the elements and secures an easy outlet to the surface for the young locust when hatched. The eggs resemble in shape grains of small rice and are about 1/4 inch long. The eggs hatch in from twenty-five to sixty days, usually about forty days, but the period may vary a little according to temperature, humidity, etc. The young locusts are known as "hoppers," in which stage they pass some forty-five or fifty days before arriving at the fully developed stage known as "fliers." To reach the "flying" or "migratory" stage they pass through six different states, changing the colour of their skin several times, gradually approaching to full growth, and finally growing wings. They have no quiescent stage, and whilst they are naturally yet incapable of flight, their locomotive powers are very considerable, and they are very destructive, for their voracity is great. Comparatively speaking, the flying locusts do less damage to the growing crops than the hoppers, who devour everything clean before them. It is interesting to state that the "hoppers" in the first stage are in length about 7 to 9 mm., or not quite one-third of an inch, and that the feelers have thirteen divisions, extending to twenty-seven divisions at full growth. During the cold weather they usually gather together in thousands, clinging closely to all kinds of vegetation and to each other. In this season the general rule seems to be that comparatively little food is taken of any kind. For the purpose of watching the development of their eggs, several hundred locusts have been opened during the winter months by entomologists, and invariably their cases have been found empty. Perhaps the most feasible suggestion as to the cause of their migratory impulse is that locusts naturally breed in dry sandy districts in which food is scarce, and are thus impelled to wander in order to procure the necessaries of life.