142 Journal of the Asiatic Society of Bengal. [N.S., XIX, 
(1) The suction theory has been very ably negatived by 
Dr. Weitlaner. He has clearly shown by his experiments 
(such as placing long threads between the lamellae to avoid the 
creation of vacua and subjecting the animal to a vacuum, an 
finding in both instances that the pads acted efficiently as 
in normal circumstances) that a vacuum or a series of vacua 
have little to do with the adhesive property of the pads. 
Moreover, the facts that a dead animal (freshly killed) can be 
made to stick to a smooth vertical surface and that a wet 
surface renders the pad relatively inefficient, also point to the 
same conclusion. As has been demonstrated by Kunitzky 
there is no definite structure in the lamellar pads which 
could prevent air from entering between the lamellae when 
they were raised after having been pressed flat against an 
opposing surface. 
(2) The adpression theory of Kunitzky, which chiefly 
tived by the fact that a dead animal in which these blood 
ad 
a smooth vertical surface. The structure of the pad clearly 
shows that the deep grooves between the lamellae cannot 
easily be filled up by the distension of internal blood spaces. 
It can, moreover, be readily seen in the foot of a Gecko 
clinging to a vertical glass surface that the grooves between 
the lamellae are open at both ends and that they are fairly 
deep and spacious. 
H. R. Schmidt’s theory of the electrification of the 
setose processes by rubbing against an opposing surface is 
rather imaginary than practical and does not bear close 
scrutiny. 
My own views regarding the adhesive action of the pads 
are similar to those already advanced to account for the 
adhesion of the cephalic disc of Echeneis and of the striated 
apparatus found on the under surface of certain fish of 
cesses and to replace them as they are worn out. The same 
fact is clear from observation 8 recorded above. The feeling 
of stickiness, which is caused by the typically padded adhesive 
digits when a Gecko hangs from one’s finger, is probably due 
_to the clinging action of the setose processes. Friction depends 

1 Hora, Nature, p. 668 (May 19, 1923); Rec, Ind. Mus., XXV, PP- 
587-591 (1923). 
