The second species is only half the size of the Common Cicada and is known in the district by the name of the Cacan, a fairly accurate imitation of his peculiar rattle. This is the Ash Cicada of the naturalists; and he is far more alert and more suspicious than the first. His harsh loud song consists of a series of Can! Can! Can! Can! with not a pause to divide the ode into strophes. Its monotony and its harsh shrillness make it a most unpleasant ditty, especially when the orchestra is composed of some hundreds of executants, as happens in my two plane-trees during the dog-days. At such times it is as though a heap of dry walnuts were being shaken in a bag until the shells cracked. This irritating concert, a veritable torment, has only one slight advantage about it: the Ash Cicada does not start quite so early in the morning as the Common Cicada and does not sit up so late at night. Although constructed on the same fundamental principles, the vocal apparatus displays numerous peculiarities which give the song its special character. The sound-chamber is entirely lacking, which means that there is no entrance-window either. The cymbal is uncovered, just behind the insertion of the hind-wing. It again is a dry, white scale, convex on the outside and crossed by a bundle of five red-brown nervures. The first segment of the abdomen thrusts forward a short, wide tongue, which is quite rigid and of which the free end rests on the cymbal. This tongue may be compared with the blade of a rattle which, instead of fitting into the teeth of a revolving wheel, touches the nervures of the vibrating cymbal more or less closely. The harsh, grating sound must, I think, be partly due to this. It is hardly possible to verify the fact when holding the creature in our fingers: the startled Cacan does anything at such times rather than emit his normal song. The lids do not overlap; on the contrary, they are separated by a rather wide interval. With the rigid tongues, those appendages of the abdomen, they shelter one half of the cymbals, the other half of which is quite bare. The abdomen, when pressed with the finger, does not open to any great extent where it joins the thorax. For the rest, the insect keeps still when it sings; it knows nothing of the rapid quivering of the belly that modulates the song of the Common Cicada. The chapels are very small and almost negligible as sounding-boards. There are mirrors, it is true, but insignificant ones, measuring scarcely a twenty-fifth of an inch. In short, the mechanism of sound, which is so highly developed in the Common Cicada, is very rudimentary here. How then does the thin clash of the cymbals manage to gain in volume until it becomes intolerable?