Cuar. II. MAURANDIA. 69 
these sides; in 24 hrs. subsequently, they straightened 
themselves. Next day they were rubbed on the 
opposite sides, and they became perceptibly curved 
towards these sides. Two other and younger pe- 
duncles (three-fourths of an inch in length) were 
lightly rubbed on their adjoining sides, and they be- 
came so much curved towards one another, that the 
ares of the bows stood at nearly right angles to their 
previous direction ; and this was the greatest movement 
seen by me. Subsequently they straightened them- 
selves. Other peduncles, so young as to be only 
three-tenths of an inch in length, became curved when 
rubbed. On the other hand, peduncles above 14 inch 
in length required to be rubbed two or three times, 
and then became only just perceptibly bowed. Loops 
of thread suspended on the peduncles produced no 
effect ; loops of string, however, weighing ‘82 and 1-64 
of a grain sometimes caused a slight curvature; but 
they were never closely clasped, as were the far lighter 
loops of thread by the petioles. 
In the nine vigorous plants observed by me, it is 
certain that neither the slight spontaneous movements 
nor the slight sensitiveness of the flower-peduncles 
aided the plants in climbing. If any member of the 
Scrophulariaceee had possessed tendrils produced by 
the modification of flower-peduncles, I should have 
thought that this species of Mawrandia had perhaps 
retained a useless or rudimentary vestige of a former 
habit; but this view cannot be maintained. We may 
suspect that, owing to the principle of correlation, 
