Some species are destitute of wings, and resemble so exactly dry sticks that it is impossible to tell the difference. The best known is the _Bacillus (Phasma) Rossia_ (Fig. 303), which is found in the south of France. This inoffensive insect walks gently along the branches of trees, and likes to repose in the sun, its long antennæ-like legs stretched out in front. Others of the genus _Phyllium_ are provided with wings, and have altogether the appearance of the leaves on which they live; such are the Walking Leaves of the East Indies. According to Cunningham, all these insects are of solitary and peaceable habits. They are only to be met with alone or in pairs, drawing themselves gently along on shrubs, on which they pass the hottest months of the year. Some of them, when they are seized, emit a milky liquid of a very strong and disagreeable odour. [Illustration: Fig. 303.--Phasma Rossia--male, female, and larva.] Those Orthoptera which we have already mentioned had all their six legs adapted to running, and are called _Cursoria_. Those which jump, to which we now come, have their hind-legs stronger and thicker, which enables them to leap, and are on that account called _Saltatoria_. This section comprises three families, which have for their principal types the Crickets, Locusts, and Grasshoppers. All these insects resemble each other in the disproportion which exists between their hind-legs and the other pairs. Another characteristic which is common to them consists in the song of the males. This song, so well known, which seems to have for its object to call the females, is nothing but a sort of stridulation or screeching, produced by the rubbing together of the wing cases, or elytra. But the mechanism by which this is produced varies a little in all the three kinds. With the Crickets the whole surface of the wing cases is covered with thick nervures, very prominent and very hard, which cause the noise the insect produces in rubbing the elytra one against the other. With the Locusts, there exists only at the base of the elytra a transparent membrane called the mirror, which is furnished with prominent nervures, and produces the screeching noise. And, lastly, in the Crickets the thighs and elytra are provided with very hard ridges. The thighs, being passed rapidly and with force over the nervures of the elytra, produce the sound, in the same way as a fiddle-bow when drawn across the strings of a violin. In all these insects the male alone is endowed with the faculty of producing sound. The Crickets and Grasshoppers have very long and thin antennæ, whilst the Locusts have short antennæ, and either flattened or filiform, or swelling out at one extremity like a club. The female of the first two is provided with an ovipositor in the shape of an auger. We will study successfully the three types of these families, that is to say, the Crickets, the Locusts, and the Grasshoppers.