Though the sounds made by insects may not in themselves be musical, according to our standard of music, yet many insect performers give us great pleasure, perhaps because of the pleasant memories which they call up. Who among us does not love the hum of the bee? How delightful is the lazy drone of the great steely-blue dor-beetle, as he rambles along in the twilight of a summer night! The lively chirping of the cricket, too, has inspired more than one poet, and the great novelist, Charles Dickens, used it in a well-known story.

The simplest means of making a noise is that used by the beetle known by the grim name of the 'death-watch.' In our own houses this little beetle often causes great alarm by the ticking or tapping sound which it makes by striking its head against the wall. Ignorant people look upon this noise as a warning of approaching death; but, really, it is meant to charm and attract any other beetles of the kind which may be within hearing!

But many insects, like the crickets and grasshoppers, have a specially constructed instrument on which they play. Fig. 1 shows a part of the instrument used by an American grasshopper. It is formed by a row of tiny teeth, marked t, placed along the inner side of the thigh of the great leaping leg. When this creature feels very happy, or wants to charm his mate, he produces a shrill sound by rubbing these teeth across the hard 'nervures,' or wing 'veins.' What these teeth are really like can be seen in the lower part of the illustration, which shows eight little spear-heads set in sockets. These are 'teeth,' which act much as a comb would do if drawn lightly over a tightly stretched wire.

The 'stridulation,' as this form of musical production is called, in some locusts is so loud that it can be heard on a still night for a distance of a mile. Some South American locusts are such wonderful performers that the Indians keep them in wicker cages, in order that they may enjoy the playing. There is a North American locust which is quite famous as a musician. It is known as the Katydid, on account of its peculiar notes, which resemble the words Katy-did-she-did. This note is kept up throughout the night. Our field-cricket plays by rubbing a row of teeth, about one hundred and thirty in number, placed on the under side of one of the supporting rods, or 'veins,' of the wings, against another rod very like it, but without teeth, in the upper surface of the opposite wing. First one wing is rubbed over the other, and then the process is reversed.

A near relative of the grasshopper, the cicada of North America and of Southern Europe (fig. 2), has a really wonderful instrument, rather like a kettle-drum. But it is an unusual sort of kettle-drum, for it is played from within. The drum-heads are shown in fig. 3, marked d, one on each side of the creature, like the drums on a cavalry horse, except that they are underneath the animal in the case of the cicada. If the 'skin' of the drum be removed, a very complicated instrument is seen, and this, by causing vibrations, increased by the tightly stretched drum-head, gives rise to the sounds for which these insects have long been famous.

The great traveller-naturalist, Fritz MÜller, tells us that musical contests between two or three rival cicadas—only the males play—often take place. As soon as one had finished his song, another immediately began, then another, and so on all through the night. Another naturalist, Bates, tells that when in the Amazons he used to listen to the cicadas, which began with sunset. The tune began with a jarring sound, and ended in a long loud note, like 'the steam-whistle of a locomotive engine!'

In insects which hum the sound mainly comes from the abdomen. In flies and humble-bees, for example, the 'voice' is caused by air rushing out from the mouths of the air or breathing-tubes. But these sounds are deepened by the vibration of the wings. Those who know something of music will understand what is meant when they are told that the note of the honey-bee on the wing is A; its ordinary 'voice,' however, is an octave higher, and often goes to B and C. From the note produced by the wing, the speed with which it is vibrated can be reckoned. Thus, the house-fly, which produces the sound F, vibrates its wings 21,120 times a minute, or 335 times a second; the bee, which makes the note A, 26,400 times a minute, or 440 times a second!

But, besides insects, there are many spiders and scorpions which may claim to be musical. The instrument of the spider is formed on the same principle as that of the grasshopper—that is to say, by a raised tooth-like edge, which can produce vibrations. Beneath the front of a spider's head there is, on each side, a stout jaw, ending in a long, movable fang, like a claw. Behind this jaw is a short leg, formed like a walking leg, and known as the 'palp.' It is never used, however, for walking, but is carried straight forwards, so that the inner surfaces of its joints are close to the outer surface of the jaw. Now, whenever the 'palp' is moved, it is rubbed against the 'teeth' in the jaw, and this consequently, in many spiders, produces a sound like the humming of a bee! In some spiders which have this apparatus, the sound produced cannot be heard by human ears.

It is to be noted that, whatever the sound produced, its purpose is to serve one of two very different ends. It may be used, as in some spiders, when it is found only in the males, to charm its mate in courting; for she has a very bad temper, and must be approached most cautiously. But in the case of the huge bird-eating spiders, this curious buzzing sound appears to be made for the purpose of frightening its enemies, which, connecting the buzzing sound with the power of stinging, give the spider a wide berth as soon as the buzzing begins! To make itself appear more terrible, the spider raises the fore part of the body and legs high in the air, and thus, partly by this threatening attitude, and partly by the sound, persuades those about to attack that 'discretion is the better part of valour!'

The scorpion hisses. Some describe the noise as like that produced by rubbing the finger-nail over the hairs of a stiff tooth-brush. The vibrating instruments are found in different places, according to the species of scorpion. But the plan of its construction is the same in all, and is like that of the spider. Thus, in some species (as in fig. 4) there are, at the outer side of the base of the great pair of pincers, a number of sharp spinelets, shaped like a tiger's 'fang.' These make up the 'scraper.' Against it the scorpion rubs a number of tubercles, or little rounded bodies, which are seated on the base of the first pair of walking-legs; these form the 'rasp.' The movement of the rasp on the scraper produces the hissing sound. Sometimes the hissing is produced by a similar rasp and scraper placed on the inner surface of the little pincers which project in front of the body, between the two great pincers. In other cases the rasp and scraper are found, the rasp on the top of the base of the little pincer, the scraper on the under surface of the overhanging shield of the body. But, however formed, the noise produced is similar, and appears to be meant to terrify enemies. This purpose is further aided by the habit the creature has, when angry, of turning the poisonous sting at the end of the tail over the back.

W. P. Pycraft, F.Z.S., A.L.S.