Cuar, IV. CUCURBITACE. . 129 
tendrils, are from 15 to 16 inches in diameter. During 
the revolving movement, the internodes become 
successively curved to all points of the compass; 
in one part of their course they are often inclined, 
together with the tendrils, at about 45° to the horizon, 
and in another part stand vertically up. There was 
something in the appearance of the revolving internodes 
which continually gave the false impression that their 
movement was due to the weight of the long and 
spontaneously revolving tendril ; but, on cutting off the 
latter with sharp scissors, the top of the shoot rose only 
a little, and went onrevolving. This false appearance 
is apparently due to the internodes and tendrils all 
curving and moving harmoniously together. 
A revolving tendril, though inclined during the 
greater part of its course at an angle of about 45° (in 
one case of only 37°) above the horizon, stiffened and 
straightened itself from tip to base in a certain 
part of its course, thus becoming nearly or quite 
vertical. I witnessed this repeatedly ; and it occurred 
both when the supporting internodes were free and 
when they were tied up; but was perhaps most con- 
spicuous in the latter case, or when the whole shoot 
happened to be much inclined. The tendril forms a 
very acute angle with the projecting extremity of the 
stem or shoot; and the stiffening always occurred as 
the tendril approached, and had to pass over the shoot 
in its circular course. If it had not possessed and 
exercised this curious power, it would infallibly have 
struck against the extremity of the shoot and been 
