Finally, to ascertain whether the lobes independently of the petiole oscillated, the petiole of an old leaf was cemented close to the blade with shellac to the top of a little stick driven into the soil. But before this was done the leaf was observed, and found to be vigorously oscillating or jerking; and after it had been cemented to the stick, the oscillations of about 2/1000 of an inch still continued. On the following day a little infusion of raw meat was placed on the leaf, which caused the lobes to close together very slowly in the course of two days; and the oscillations continued during this whole time and for the next two days. After nine additional days the leaf began to open and the margins were a little everted, and now the apex of the glass filament remained for long periods motionless, and then moved backwards and forwards for a distance of about 1/1000 of an inch slowly, without any jerks. Nevertheless, after warming the leaf with a taper held close to it, the jerking movement recommenced. This same leaf had been observed 2½ months previously, and was then found to be oscillating or jerking. We may therefore infer that this kind of movement goes on night and day for a very long period; and it is common to young unexpanded leaves and to leaves so old as to have lost their sensitiveness to a touch, but which were still capable of absorbing nitrogenous matter. The phenomenon when well displayed, as in the young leaf just described, is a very interesting one. It often brought before our minds the idea of effort, or of a small animal struggling to escape from some constraint. (16.) Eucalyptus resinifera (Myrtaceae, Fam. 94).—A young leaf, two inches in length together with the petiole, produced by a lateral shoot from a cut-down tree, was observed in the usual manner. The blade had not as yet assumed its vertical position. On June 7th only a few observations were made, and the tracing merely showed that the leaf had moved three times upwards and three downwards. On the following day it was observed more frequently; and two tracings were made (see A and B, Fig. 108), as a single one would have been too complicated. The apex changed its course 13 times in the course of 16 h., chiefly up and down, but with some lateral movement. The actual amount of movement in any one direction was small. Fig. 108. Eucalyptus resinifera: circumnutation of a leaf, traced, A, from 6.40 A.M. to 1 P.M. June 8th; B, from 1 P.M. 8th to 8.30 A.M. 9th. Apex of leaf 14½ inches from the horizontal glass, so figures considerably magnified.