It is poorer still in the two dwarf Dectici of my neighbourhood, Platycleis intermedia, Serv., and P. grisea, Fab., both of whom are common in the long grass, where the ground is stony and exposed to the sun, and quick to disappear in the undergrowth when you try to catch them. These two fat songsters have each had the doubtful privilege of a place in my cages. Here, in a blazing sun beating straight upon the window, are my little Dectici crammed with green millet-seeds and also with game. Most of them are lying in the hottest places, on their bellies or sides, with their hind-legs outstretched. For hours on end they digest without moving and slumber in their voluptuous attitude. Some of them sing. Oh, what a feeble song! The ditty of the Intermediary Decticus, with its strophes and pauses alternating at equal intervals, is a rapid fr-r-r-r similar to the Coaltit’s, while that of the Grey Decticus consists of distinct strokes of the bow and tends to copy the Cricket’s melody, with a note which is hoarser and, in particular, much fainter. In both cases, the feebleness of the sound hardly allows me to hear the singer a couple of yards away. And to produce this music, this insignificant and only just perceptible refrain, the two dwarfs have all that their big cousin possesses: a toothed bow, a tambourine, a friction-nervure. On the bow of the Grey Decticus I count about forty teeth and eighty on that of the Intermediary Decticus. Moreover, in both, the right wing-case displays, around the mirror, a few diaphanous spaces, intended no doubt to increase the extent of the vibrating portion. It makes no difference: though the instrument is magnificent, the production of sound is very poor. With this same mechanism of a drum and file, which of them will achieve any progress? Not one of the large-winged Locustidæ succeeds in doing so. All, from the biggest, the Grasshoppers, Dectici and Conocephali, down to the smallest, the Platycleis, Xiphidion and Phaneropteron, set in motion with the teeth of a bow the frame of a vibrating-mirror; all are, so to speak, left-handed, that is to say, they carry the bow on the lower surface of the left wing-case, overlapping the right, which is furnished with the tympanum; all, lastly, have a thin, faint trill which is sometimes hardly perceptible. One alone, modifying the details of the apparatus without introducing any innovation into the general structure, achieves a certain power of sound. This is the Vine Ephippiger, who does without wings and reduces his wing-cases to two concave scales, elegantly fluted and fitting one into the other. These two disks are all that remains of the organs of flight, which have become exclusively organs of song. The insect abandons flying to devote itself the better to stridulation.