414 CLIMBING PLANTS. 
the branch which corresponds with the sub-peduncle one 
single flower-bud ! 
Ampelopsis quinquefolia (Fig. 90, tendril, with the young 
leaf. Fig. 91, tendril, several weeks after its attachment to 
a wall, with the branches thickened and spirally contracted, 
and with the extrem- 
Fig. 89. 
ities developed into 
disks. The unattached 
branches have with- 
ered and dropped off.) 
climbs by tendrils like 
the grape-vine, but in 
addition. has a way of 
holding fast to plain 
surfaces by means of 
little disks or cush- 
ions. . These disks are 
apparently never de- 
veloped without a con- 
tact with some object. 
A tendril which has 
not become attached 
to any body does not 
contract spirally ; and 
in course of a week or 
Grape-vine, 
two shrinks into the 
finest thread, withers and drops off. An attached tendril, ou 
the other hand, contracts spirally, and thus becomes highly 
elastic ; so that when the main foot-stalk is pulled, the strain 
is equally distributed to all the attached disks. During the 
following winter it ceases to live but remains firmly attached 
to the stem and to the surface of attachment. The gain in 
strength and durability in a tendril after its attachment is 
something wonderful. They adhere still strong after an 
exposure to the weather for fourteen or fifteen years. One 
single lateral branchlet of a tendril, estimated to be at least 
