Sir Evebarb Hom li’s farther observations, &c. 323 
of life ; which will assist him in giving a better arrangement 
of the subdivisions of this numerous class than has been 
hitherto done. 
This structure of the feet of insects, now that it is known, 
can be very readily demonstrated by looking at the move- 
ments of the feet of any insect upon the inside of a glass 
tumbler, through a common magnifying glass ; the different 
suckers are readily seen separately to be pulled off from the 
surface of the glass, and reapplied to another part. 
The pockets on the under surface of the toes of the lacerta 
gecko, as they are represented in Plate XVII, show that 
v/hat looked like a pectinated edge when seen through a 
common magnifying glass, consists of a complex structure, 
composed of rows of a beautiful fringe, which are applied to 
the surface on which the animal walks against gravity, while 
the pockets themselves are pulled up by the muscles attached 
to them, so as to form the cavities into suckers. 
In the blue bottle fly, it will be seen, in Plate XVIII, that 
the suckers are two in number, that they are connected to 
the last joint of the toe, immediately under the root of the 
claw, and have a narrow infundibular neck attached to the 
toe, which has the power of motion in every direction ; when 
these suckers are to be applied, they are separated from each 
other, and the membrane of each is expanded so as to in- 
crease the surface; but when disengaged, they become nearly 
closed, and are brought together, so as to be confined within 
the space between the two claws. 
The external edge of each sucker is beautifully serrated, and 
the concave surface is granulated. When the fly is walking 
against gravity, and its motions are observed, they all appear 
mdcccxvi. U u 
