If the weather is likely to become rainy, windy or in other respects disagreeable, spiders fix the terminating filaments, on which the whole web is sustained, unusually short. If the terminating filaments are made uncommonly long, the weather will be serene, and continue so, at least for ten or twelve days. If spiders be totally indolent, rain generally succeeds; their activity during rain is certain proof that it will be of short duration, and followed by fair and constant weather. Spiders usually make some alteration in their webs every twenty-four hours; if these changes take place between the hours of six and seven in the evening, they indicate a clear and pleasant night. "The clouds grow heavier over head— The spider strengtheneth his web." _Muscles of the Caterpillar._ Our varied movements are executed by the aid of fleshy muscles attached to the skeleton. In these, insects possess a numerical and dynamical superiority over the human race. Anatomists calculate that there are only 370 of these muscles in a man, whilst the patient Lyonet discovered more than 4000 in a single caterpillar. _A Persistent Fly._ Linnæus saw one of the flies which attack cattle follow a reindeer an entire day, though dragging its sled at a gallop over the snow. The fly flew almost continuously by its side, watching for the moment when it might introduce one of its eggs beneath the skin. _Phosphorescent Insects._ In tropical America there are phosphorescent insects of remarkable splendor. In Cuba the women often inclose several of the luminous beetles in little cages of glass, which they hang up in their rooms, and this living lustre throws out sufficient light for them to work by. Travelers, in a difficult road, light their path in the middle of the night by attaching one of these beetles to each of their feet. The Creoles sometimes set them in the curls of their hair, where, like resplendent jewels, they give a fairy-like aspect to their heads. The negresses, at their nocturnal dances, scatter these brilliant insects over their robes of lace which nature provides for them, all woven from the bark of the Lagetto. _Eating Clouds._