25 
fact is forcibly obtruded on our notice. A certain 
definite mode of being is generally adapted to a cer- 
tain definite end. But no absolute necessity binds 
the means to the end. The mode generally adopted 
may be, and doubtless is, the best; but the varieties 
of modes adapted to similar conditions demonstrate 
that the end has not influenced and controlled the 
contriving and adapting power, which might have 
chosen another mode, and which does occasionally 
adapt widely different modes to the same purposes. 
In man the principal organs of locomotion are the 
lower limbs: in the bat tribes, and in the aquatic 
mammalia, they are the fore limbs. In most qua- 
drupeds the locomotive power is equally allotted to 
all the four extremities. 
If we survey the seven different classes of ani- 
mals, so widely separated from each other in their 
leading differential characters, and by their general 
locality, we shall readily observe a capability pos- 
sessed by several in each class of animals, and in 
the vegetable kingdom, to subsist in a local condi- 
tion for which the generality are unfitted. Of these, 
the first and second columns notice familiar in- 
stances. The lion is thus viewed in analogical ratio 
to the otter and manati, as the eagle to the coot and 
the penguin; as the boa constrictor to the turtle, or 
allegator, or siren; as the flying exoccetus, and eel, 
and callichthys to the herring, pilchard, and trout ; 
method itself is different, that we might see it is not the effect of 
surd necessity.” 
