CLIMBING PLANTS. 417 
platina wire, one-fiftieth of a grain in weight, gently placed 
on the concave point, caused two tendrils to become hooked. 
After a touch the tendril began to move in twenty-five sec- 
onds. Dr. Asa Gray saw tendrils of Sicyos move in thirty 
seconds. Other tendrils move in a few minutes; in the: 
Dicentra in half an hour; in the Smilax in an hour and a 
quarter; and in the Ampelopsis still more slowly.  Tendrils 
move to the touch of almost any substance, drops of water 
excepted. Adjoining tendrils rarely catch each other. Some 
tendrils have their revolving motion accelerated and retarded 
in moving to and from the light; others are indifferent to its 
action. America which so abounds with arboreal animals 
Fig. 92. 
Bryony. 
abounds with climbing plants; and, of the tendril-bearing 
plants examined the most admirably constructed come from 
this grand continent, namely, the several species of Big- 
nonia, Eccremocarpus, Cobea, and Ampelopsis. 
Root Climbers.— Ficus repens climbs up walls just like 
ivy; when the young rootlets were made to press lightly on 
slips of glass they emitted, after about a week’s interval, 
minute drops of clear fluid, slightly viscid. One small drop 
the size of half a pin’s head, was mixed with grains of sand. 
The slip of glass was left exposed in a drawer during hot 
aud dry weather. The mass remained fluid during one hun- 
dred and twenty-eight days; how much longer was not ob- 
served. The rootlets seem to first secrete a slightly viscid 
AMER. NATURALIST, VOL. IV. 53 
