Ounap. I, TWINING PLANTS. 21 
not move, a sort of hinge separating the moving and 
the motionless part of the same internode. After a 
few days, however, I found that this lower part had 
likewise recovered its revolving power. These.several 
facts show that the power of movement is not immedi- 
ately lost in the arrested portion of a revolving shoot ; 
and that after being temporarily lost it can be recovered. 
When a shoot has remained for a considerable time 
round a support, it permanently retains its spiral form 
even when the support is removed. 
When a tall stick was placed so as to arrest the 
lower and rigid internodes of the Ceropegia, at the 
distance at first of 15 and then of 21 inches from the 
centre of revolution, the straight shoot slowly and 
gradually slid up the stick, so as to become more and 
more highly inclined, but did not pass over the 
summit. Then, after an interval sufficient to have 
allowed of a semi-revolution, the shoot suddenly 
bounded from the stick and fell over to the opposite 
side or point of the compass, and reassumed its 
previous slight inclination. It now recommenced 
revolving in its usual course, so that after a semi- 
revolution it again came into contact with the stick, 
again slid up it, and again bounded from it and fell 
over to the opposite side. This movement of the 
shoot had a very odd appearance, as if it were 
disgusted with its failure but was resolved to try 
again. We shall, I think, understand this movement 
by considering the former illustration of the sapling, in 
which the growing surface was supposed to creep round 
