on ihe jeet of animals , &c. 325 
fore legs have the form of a shield, the under surface of which 
is covered with suckers, one very large, a second one-third 
smaller, and all the rest very small. In the second pair of 
feet, the corresponding joints are much narrower in propor- 
tion, and are covered on their under surface with very small 
suckers. 
All these suckers, as is seen in Fig. 13, 14, and 15, have 
long tubular necks, which show more plainly than in the 
others the mode in which the vacuum is produced ; it is exactly 
similar in its effect to that of a piece of leather with a string 
in the centre, applied in a moistened state to the surface of 
a stone. 
Having explained this apparatus, so .beautifully contrived 
to attach the feet to the surface on which the animal moves, 
I shall conclude this Paper by an account of a structure of a 
very different kind, for the purpose of taking off the jar when 
the body of the insect is suddenly brought from a state of 
motion to a state of rest ; this is met with in the grylli and 
locustse. Some of them have suckers at the ends of the toes, 
others have not. 
In a species of gryllus with a corcelated thorax, brought 
from Abyssinia, by Mr. Salt, the feet are made up of three 
joints; on the under surface of the first are three pair of glo- 
bular cushions, filled with an elastic fibrous substance, looser 
in its texture towards the circumference, which renders it still 
more elastic ; under the second joint is one pair of similar 
cushions, and under the last joint, immediately between the 
daws, fs a large oval sucker. A similar sucker is met with 
between the claws in a British grasshopper, the acrydium 
biguttulum (Lair.) These are common to all the six feet. 
They are represented in Plate XXL 
U112 
