Here again we find that playful experimentation is essential, and, according to Raehlmann, it commonly appears toward the end of the fifth week, rarely earlier.[145] That Preyer’s boy on the twenty-third day followed with his eyes a slowly moving light was probably an instance of forced development, as a result of much experimenting. On the twenty-ninth day the same child crowed aloud at the sight of a swaying tassel. On the sixty-second day he gazed at a swinging lamp with constant manifestations of delight for nearly half an hour, but his eyes did not follow the swing of the pendulum; they moved, it is true, now left, now right, but not in time with the lamp. “On the one hundred and first day a pendulum making forty complete swings in a minute was for the first time followed with mechanical exactness by his glance.”[146] As his capacity for following the movement increased, the greater his interest in it became. A dog racing away or leaping about the child, the fast horse, the hopping toad, the crawling worm or gliding snake, running water, leaping flame, a rolling wagon, and, more than all, the fast-rushing train, with its cloud of steam—all these excite a really passionate sympathy. The smoke of a cigar, too, gives great satisfaction, and if a father knows how to make the beautiful blue rings he must at once renounce his peaceful contemplative enjoyment of his own play, for the youngster will demand a very different _tempo_ in the repetition than is agreeable to him. In enumerating instances of animal motion I omitted one because it deserves more extended notice—namely, the flight of insects, in which children take such lively interest. The common illusion that an insect which has been caught can be induced to fly away by the recital of a form of words is highly interesting, in itself considered as well as in view of its probable origin. May not such poetic formulæ be traceable to a religious or at least superstitious origin? The commonest of these rhymes are those addressed to the ladybird (_Coccinella septempunctata_) and the June bug. Rochholz has made a collection of the names of the former, and found that in India it was sacred to the god Indra, and among the old Germans to Frega. I give two German forms of the verse: “Muttergotteshühle, Mückenstühle, Fliege auf, fliege auf! Wohl über die Bussenberg, Dass es besser Wetter wird.” “Marienkäferchen, wann wird Sonne sein? Morgen oder heut? Flieg weg in den Himmel!” An English one is: “Ladybird, ladybird, Fly away home; If you’ll be quick, The sunshine will come.” All are familiar with the adjuration to the June bug. French children sing: “Hanneton, vole, vole! Ton mari est a l’école, Il a dit qu’si tu volais, Tu aurais d’la soupe au lait Il a dit qu’si tu n’volais pas, Tu aurais la tête en bas.” To the butterfly, which is not so easily caught, the invitation is to alight: “Molketewer sett di, Kömmt e Pogg de frett di!”