_Clematis vitalba_.—The plants were in pots and not healthy, so that I dare not trust my observations, which indicate much similarity in habits with _C. flammula_. I mention this species only because I have seen many proofs that the petioles in a state of nature are excited to movement by very slight pressure. For instance, I have found them embracing thin withered blades of grass, the soft young leaves of a maple, and the flower-peduncles of the quaking-grass or Briza. The latter are about as thick as the hair of a man’s beard, but they were completely surrounded and clasped. The petioles of a leaf, so young that none of the leaflets were expanded, had partially seized a twig. Those of almost all the old leaves, even when unattached to any object, are much convoluted; but this is owing to their having come, whilst young, into contact during several hours with some object subsequently removed. With none of the above-described species, cultivated in pots and carefully observed, was there any permanent bending of the petioles without the stimulus of contact. In winter, the blades of the leaves of _C. vitalba_ drop off; but the petioles (as was observed by Mohl) remain attached to the branches, sometimes during two seasons; and, being convoluted, they curiously resemble true tendrils, such as those possessed by the allied genus _Naravelia_. The petioles which have clasped some object become much more stiff, hard, and polished than those which have failed in this their proper function. TROPÆOLUM.—I observed _T. tricolorum_, _T. azureum_, _T. pentaphyllum_, _T. peregrinum_, _T. elegans_, _T. tuberosum_, and a dwarf variety of, as I believe, _T. minus_.