Cuar. L. TWINING PLANTS. 35 
most improbable. It would be hardly possible with 
any plant which ascended above a few feet in height, 
or which lived in an exposed situation; for the stem 
could be pulled away easily from its support, with but 
little unwinding; nor could it have adhered at all, 
had not the internodes soon become moderately rigid. 
With leaf-climbers, as we shall soon see, analogous 
cases frequently occur ; but these present no difficulty, 
as the stem is secured by the clasping petioles. 
In the many other revolving and twining plants 
observed by me, I never but twice saw the movement 
reversed ; once, and only for a short space, in Ipomaa 
jucunda ; but frequently with Hibbertia dentata. This 
plant at first perplexed me much, for I continually 
observed its long and flexible shoots, evidently well 
fitted for twining, make a whole, or half, or quarter 
circle in one direction and then in an opposite 
direction; consequently, when I placed the shoots 
near thin or thick sticks, or perpendicularly stretched 
string, they seemed as if constantly trying to ascend, 
but always failed. I then surrounded the plant with a 
mass of branched twigs; the shoots ascended, and 
passed through them, but several came out laterally, and 
their depending extremities seldom turned upwards as 
is usual with twining plants. Finally, I surrounded 
a second plant with many thin upright sticks, and 
placed it near the first one with twigs; and now 
both had got what they liked, for they twined up 
the parallel sticks, sometimes winding round one and 
gometimes round several; and the shoots travelled 
