Now as to the manner in which insects are caught by the leaves of _Dionæa muscipula_. In its native country they are caught in large numbers, but whether they are attracted in any special way no one seems to know. Both lobes close with astonishing quickness as soon as a filament is touched, and as they stand at less than a right angle to each other, they have an excellent chance of capturing any intruder. The chief seat of the movement is near the mid-rib, but is not restricted to this part. Each lobe, when the lobes come together, curves inwards across its whole breadth, the marginal spikes alone not becoming curved. From the curving inwards of the two lobes, as they advance towards each other, the straight marginal spikes intercross by their apices at first, and ultimately by their bases. The leaf is then completely shut and encloses a shallow cavity. If made to shut merely by the touching of one of the sensitive filaments, or by the inclusion of an object not yielding soluble nitrogeneous matter, the two lobes retain their inwardly concave form until they re-expand. The re-expansion, when no organic matter is enclosed, varies according to circumstances, a leaf in one instance being fully re-expanded in thirty-two hours. But the lobes, when soluble nitrogeneous matter is included, instead of remaining concave, thus containing within a concavity, slowly press closely together throughout their entire breadth, and as this takes place the margins gradually become a little everted, so that the spikes, which at first intercrossed, at last project in two parallel rows. So firmly do they become pressed together that, if any large insect has been caught, a corresponding projection is clearly visible on the outside of the leaf. When the two lobes are thus completely closed, they resist being opened, as by a thin wedge driven with astonishing force between them, and are generally ruptured rather than yield. If not ruptured, they close again with quite a loud flap. The slow movement spoken of, excited by the absorption of diffused animal matter, suffices for its final purpose, whilst the movement brought on by the touching of one of the sensitive filaments is rapid, and thus indispensable for the capturing of insects. Leaves remain shut for a longer time over insects, especially if the latter are large, than over meat. In many instances where they have remained for a long period over insects naturally caught, they were more or less torpid when they reopened, and generally so much so during many succeeding days that no excitement of the filaments caused the least movement. Vigorous leaves will sometimes devour prey several times, but ordinarily twice, or, quite often, once is enough to render them unserviceable.