V 
SirE. Home on the feet of animals 
weighing five ounces three quarters, avoirdupoise weight, 
which has enabled me to ascertain the peculiar mechanism by 
which the feet of this animal can keep their hold of a smooth 
hard perpendicular wall, and carry up so large a weight as 
that of its body. 
The foot of the Gecko has five toes, at the end of each of 
which, except the thumb, is a very sharp claw much curved ; 
on the under surface of each toe are sixteen transverse slits, 
leading to so many cavities or pockets, the depth of which is 
nearly equal to the length of the slit that forms the orifice ; 
they all open forwards, and the external edge of each opening 
is serrated, like the teeth of a small-toothed comb. The 
cavities, or pockets, are lined with a cuticle, and the serrated 
edges are covered with it. On each side of the bones of the 
toe, which are three in number, is situated a large muscle of 
an oval form ; its origin is at the tarsus, the fleshy portion 
extends to the end of the first bone of the toe, and the tendons 
of both are continued on to the claw, which is moved by these 
muscles. From the tendons of these large muscles, two sets 
of smaller muscles originate ; one pair of which is lost upon 
the posterior surface of each of the cavities, or pockets, that 
lie immediately over them. 
The large muscles, by their contraction, draw down the 
claw, and necessarily put the small muscles that go off from 
the tendons of the larger upon the stretch, so that under such 
circumstances they act to a greater advantage. When these 
contract, they open the orifices of the cavities, or pockets, to 
which they belong, and turn down the serrated edge upon the 
surface on which the animal stands. 
On each side of the toes there is a loose fold of skin, giving 
