If the glands on the disc are repeatedly touched or brushed, although no object is left on them, the marginal tentacles curve inwards. So again, if drops of various fluids, for instance of saliva or of a solution of any salt of ammonia, are placed on the central glands, the same result quickly follows, sometimes in under half an hour. * ‘Bot. Zeitung,’ 1860, p. 246. [page 10] The tentacles in the act of inflection sweep through a wide space; thus a marginal tentacle, extended in the same plane with the blade, moves through an angle of 180o; and I have seen the much reflected tentacles of a leaf which stood upright move through an angle of not less than 270o. The bending part is almost confined to a short space near the base; but a rather larger portion of the elongated exterior tentacles FIG. 4. (Drosera rotundifolia.) Leaf (enlarged) with all the tentacles closely inflected, from immersion in a solution of phosphate of ammonia (one part to 87,500 of water.) FIG. 5. (Drosera rotundifolia.) Leaf (enlarged) with the tentacles on one side inflected over a bit of meat placed on the disc. becomes slightly incurved; the distal half in all cases remaining straight. The short tentacles in the centre of the disc when directly excited, do not become inflected; but they are capable of inflection if excited by a motor impulse received from other glands at a distance. Thus, if a leaf is immersed in an infusion of raw meat, or in a weak solution of ammonia (if the [page 11] solution is at all strong, the leaf is paralysed), all the exterior tentacles bend inwards (see fig. 4), excepting those near the centre, which remain upright; but these bend towards any exciting object placed on one side of the disc, as shown in fig. 5. The glands in fig. 4 may be seen to form a dark ring round the centre; and this follows from the exterior tentacles increasing in length in due proportion, as they stand nearer to the circumference. The kind of inflection which the tentacles undergo is best shown when the gland of one of the long exterior FIG. 6. (Drosera rotundifolia.) Diagram showing one of the exterior tentacles closely inflected; the two adjoining ones in their ordinary position.)