While most spiders obtain their food either by patiently waiting in ambush or by catching it with a bound, the enormous mygales, or trap-door spiders, run about with great speed in and out, behind and around every object, searching for what they may devour, and from their size and rapid motions exciting the horror of every stranger. Their body, which sometimes attains a length of three inches, while their legs embrace a circle of half a foot in diameter, is covered all over with brown, reddish brown, or black hair, which gives them a funereal appearance, while their long fangs armed with sharp hooks proclaim at once what formidable antagonists they must be to every insect that comes within their reach. Though some species are found in Southern Europe, in Chili, or at the Cape, yet they are chiefly inhabitants of the torrid zone, both in the old and the new world. Some of them weave cells between the leaves, in the hollows of trees or rocks, while others dig deep tubular holes in the earth, which they cover over with a lid, or rather with a door formed of particles of earth cemented by silken fibres, and closely resembling the surrounding ground. This door or valve is united by a single hinge to the entrance at its upper side, and is so balanced that, when pushed up, it shuts again by its own weight; nay, what is still more admirable, on the interior side opposite to the hinge a series of little holes may be perceived, into which the mygale introduces its claws to keep it shut, should any enemy endeavour to open it by force. The interior of the nest, which is sometimes nine inches deep, is lined with a double coat of tapestry, the one nearest the wall, which is of a coarser tissue, being covered with a pure white silken substance like paper. New-comers into the country which the trap-door spider inhabits, are often as surprised as Ali Baba in the ‘Forty Thieves’ by seeing the ground open, a little lid lifted up, and a grim black-haired spider peer about as if to reconnoitre the position before sallying out of its fortress. At the least movement on the part of the spectator, down drops the spider disappearing into its hole, the door closes and the astonished observer, unable to find its traces in the apparently unbroken soil doubts whether his eyes have not deceived him. Nothing short of actual violence will induce the trap-door spider to vacate the premises it has so admirably constructed. It holds on with all its might and will permit the earth to be excavated around its burrow and the whole nest to be removed without deserting its home. But all its energy vanishes as soon as it is removed from the burrow it so pertinaciously defended; it then loses all its activity, remains fixed to the spot as if stupified, or at the best walks languidly about like one who has lost all that made existence valuable.