The bare fact that a horse _can_ be influenced by occult mental powers proves the close parallelism that exists between the brains of men and beasts. The Trap-Door Spider. Let no one suppose for one moment that animal mind and intelligence is limited to the brain-bearing vertebrates. The scope and activity of the notochord in some of the invertebrates present phenomena far more wonderful per capita than many a brain produces. Interesting books have been written, and more will be written hereafter, on the minds and doings of ants, bees, wasps, spiders and other insects. Consider the ways and means of the ant-lion of the East, and the trap-door spider of the western desert regions. As one object lesson from the insect world, I will flash upon the screen, for a moment only, the trap-door spider. This wonderful insect personage has been exhaustively studied by Mr. Raymond L. Ditmars, in the development of a series of moving pictures, and at my request he has contributed the following graphic description of this spider's wonderful work. "The trap-door spiders, inhabiting the warmer portions of both the Old and New Worlds, dig a deep tunnel in the soil, line this with a silken wallpaper, then construct a hinged door at the top so perfectly fitted and camouflaged with soil, that when it is closed there is no indication of the burrow. Moreover, the inside portion of the door of some species is so constructed that it may be "latched," there being two holes near the edge, precisely placed where the curved fangs may be inserted and the door held firmly closed. Also, the trap-door of a number of species is so designed as to be absolutely rain-proof, being bevelled and as accurately fitting a corresponding bevel of the tube as the setting of a compression valve of a gasolene engine. [Illustration: THE TRAP-DOOR SPIDER'S DOOR AND BURROW By R. L. Ditmars 1. The door closed. Its top carefully counterfeits the surrounding ground. 2. The door with silken hinge, held open by a needle. 3. The spider in its doorway, looking for prey. 4. Section of the burrow and trap- door.] "The study of a number of specimens of our southern California species, which builds the cork-type door, including observations of them at night, when they are particularly active, indicates that the construction of the tube involves other material than the silken lining employed by many burrowing spiders. In the excavation of the tube and retention of the walls, the spider appears to employ a glairy substance, which thoroughly saturates the soil and renders the interior of the tube of almost cement- like hardness. It is then plastered with a thick jet of silk from the spinning glands. This interior finishing process appears to be quite rapid, a burrow being readily lined within a couple of hours.