222 
two very essential differences between such “hooks” and those 
of Strychnos, in which the curvature is certainly not directly 
caused by a change of turgidity, and when once produced is 
permanent. 
Bauhinia tomentosa. .. 
The tendrils of B. tomentosa as regards their relative stiffness 
and rigidity, the marked permanent curvature produced normally 
without contact , the secondary thickening produced when in con- 
tact, and the permanent differentiation of more irritable con- 
cave, and less irritable convex surfaces, present strong points 
of resemblance to such “hook-tendrils” as those of Strychnos. 
The tendrils are brown and hairy, they arise in opposite pairs 
and are when adult from 14 to 18 ¢.m. long. The basal 5 to 
6 c.m., are nearly straight and almost non-irritable and average 
2A) 180 in thickness. The convex back of the tendril is flat, 
whilst the concave surface is rounded from side to side. The 
thickest part of the tendril (340 : | 90) is at a point from 8 
to 10 cm. from the base and then it tapers slowly to the bluntly 
pointed apex. The terminal and most irritable part of the tendril is 
concentrically coiled, and over this region the concave surface 
is green and almost bare of hairs. The tendril coils best around 
@ support from 1 to 2 cm. thick. If the support is thinner the 
coils are loose, but coiling may take place around supports 
the diameters of which vary within the limits 0.4 cm. to 4m: 
A tendril attached for 3 weeks to a stem of 0.8 cm. diameter 
Formed et 3 coils around it and attained a maximum thickney 
of 510 . 365 (the opposite unattached tendril 330 . 180), at 
the base being OB 250 (235 . 275), whilst a weight of 3 kilo’ 
caused the attached tendril to break away at the coiled por 
tion and ¥, kilo caused the unattached tendril to straighten. 
One result of contact is, that the basal part of the tendril, 
though not in contact with anything, becomes nearly cireulat 
in transverse section. The convex surface of the distal portion 
also becomes somewhat rounded, whilst the concave surface, 
if tightly pressed to the support, becomes flattened. 
