Dr. Sharp says that these animals do very well in confinement, and he found that sliced apples and grass formed the best food for them. He watched the process of nest-making and egg-laying, and these creatures are so abundant, and the necessary appliances so simple, that we may follow his example and see it for ourselves. His arrangements were the same as for Lithobius, and he saw the female make a hollow sphere of a bit of earth, stuck together by the secretion from the salivary glands, and smooth on the inside. A small hole was left on the top, and through this she passed in from 60 to 100 eggs, closing the aperture with earth moistened with the salivary secretion. The eggs were hatched in about twelve days. The young of all the Myriapods when they leave the egg have but three pairs of legs, but the number of limbs and segments is increased at each successive moult. Having watched our Millepedes in confinement, it will be well to take a preserved specimen and examine it carefully with the pocket lens, so as to compare it with the Centipede; then to compare both with the common earthworm, and to note the points of likeness and of difference. The dark spots on each segment in the illustration show the stigmata. [Illustration: FIG. 65.--Segments of Millepede (magnified).] CHAPTER V CRUSTACEANS.--PRAWN, SHRIMP, MYSIS, CRABS; AMPHIPODS; ISOPODS The next group of Arthropod animals with which we have to deal is that of the Crusta´cea. Some or other of the members of this class are well known to everybody, if only in the shape of toothsome food--the Prawn, the Shrimp, the Lobster, the Crayfish, and the Crab. The great characteristic of this class of the Arthropod phylum is the so-called ‘shell,’ which differs greatly from true shell in being composed of chitine, hardened with salts of lime. Most of the species live in the water and breathe by means of gills or through the skin. In dealing with these creatures, some long words must be employed, if our present work on them is to be a stepping-stone to something more advanced. The difficulty is more apparent than real, and if boldly faced will soon be overcome. Our first division, or sub-class, of the Crusta´cea is that of the Malacos´traca, or animals with soft shells--a name originally adopted, as Mr. Stebbing tells us[42], ‘to distinguish such creatures as crabs and crawfish and prawns from such others as oysters and clams; not because of the absolute, but because of the comparative softness of their shells.’ Under this sub-class are grouped two Orders--the Stalked-eyed and the Sessile-eyed Crustaceans, the technical names for which are the Podophthal´ma and the Edriophthal´ma.