While there can be no doubt that the musical performances of the Crickets and Locusts play an important part in courtship, in some of the Long-horned Locusts, at any rate, the males fight furiously when mate-hunting, and to this end the head and jaws are greatly enlarged. During the progress of the duel the wings are extended and held erect, which is hardly what one would have expected, since in this position they would seem to be more exposed to danger. All the insects so far surveyed have been more or less conspicuous for their vivid hues, yet in none of these have elaborate “displays” been recorded. To find demonstrativeness of this kind one must turn apparently to a group of minute, lowly organized, dull-coloured, wingless insects with ugly misshapen heads and bodies. The sexes do not differ in appearance, but they are interesting on account of the sedulous court which the males pay to the females. The late Lord Avebury, in a Communication to the Linnean Society, remarked of them: “It is very amusing to see these little creatures (_Smynthurus luteus_) coquetting together. The male, which is much smaller than the female, runs round her, and they butt one another, standing face to face and moving backwards and forwards like two playful lambs. Then the female pretends to run away and the male runs after her. With a queer appearance of anger, he gets in front and stands facing her again; then she turns coyly round, but he, quicker and more active, scuttles round too, and seems to whip her with his antennæ; then for a bit they stand face to face, play with their antennas and seem to be all in all to one another.” The Dragon-flies are among the most beautiful of insects; they are also relatively long-lived, and they are conspicuous. Yet this beauty must be attributed to some inherent inward grace rather than to the æsthetic instincts of the female. Moreover, in the matter of size and beauty there is little to choose between the sexes; where any difference occurs the males have the advantage. Though the mode of copulation is well known, nothing has been discovered as to the means whereby male and female discover one another. It is doubtful whether this can be done by sight, for with all the beauty of their shimmering suits of mail and gauzy wings, their vision is limited to a field of a few inches. Possibly scent is their guide; at any rate, dead Dragon-flies have a vile odour.