The still closed lobes of a young leaf of Dionaea projected at right angles to the petiole, and were in the act of slowly rising.  A glass filament was attached to the under side of the midrib, and its movements were traced on a vertical glass.  It circumnutated once in the evening, and on the next day rose, as already described (see Fig. 106, p. 240), by a number of acutely zigzag lines, closely approaching in character to ellipses.  This movement no doubt was due to epinasty, aided by apogeotropism, for the closed lobes of a very young leaf on a plant which had been placed horizontally, moved into nearly the same line with the petiole, as if the plant had stood upright; but at the same time the lobes curved laterally upwards, and thus occupied an unnatural position, obliquely to the plane of the foliaceous petiole.

As the hypocotyls and epicotyls of some plants protrude from the seed-coats in an arched form, it is doubtful whether the arching of these parts, which is invariably present when they break through the ground, ought always to be attributed to epinasty; but when they are at first straight and afterwards become arched, as often happens, the arching is certainly due to epinasty.  As long as the arch is surrounded by compact earth it must retain its form; but as soon as it rises above the surface, or even before this period if artificially freed from the surrounding pressure, it begins to straighten itself, and this no doubt is mainly due to hyponasty.  The movement of the upper and lower half of the arch, and of the crown, was occasionally traced; and the course was more or less zigzag, showing modified circumnutation.

With not a few plants, especially climbers, the summit of the shoot is hooked, so that the apex points vertically downwards.  In seven genera of twining plants* the hooking, or as it has been called by Sachs, the nutation of the tip, is mainly due to an exaggerated form of circumnutation.  That is, the growth is so great along one side that it bends the shoot completely over to the opposite side, thus forming a hook; the longitudinal line or zone of growth then travels a little laterally round the shoot, and the hook points in a slightly different direction, and so onwards until the hook is completely reversed.  Ultimately it

* ‘The Movements and Habits of Climbing Plants,’ 2nd edit. p. 13. [page 272]

comes back to the point whence it started.  This was ascertained by painting narrow lines with Indian ink along the convex surface of several hooks, and the line was found slowly to become at first lateral, then to appear along the concave surface, and ultimately back again on the convex surface.  In the case of Lonicera brachypoda the hooked terminal part of the revolving shoot straightens itself periodically, but is never reversed; that is, the periodically increased growth of the concave side of the hook is sufficient only to straighten it, and not to bend it over to the