INTRODUCTION. 
^viii 
very great degree of swiftness ; but they are still 
further assisted by their spirit of; mutual de» 
fence ; the females fall into the centre ; and the 
males, forming a ring round them, oppose their 
horns to the assailants. Some animals, that feed 
upon fruits, which are to be found only at one time 
of the year, fill their holes with several sorts of 
plants, which enable them to lie concealed during 
the hard frosts of the winter, contented with their 
prison, since it affords them plenty and protection. 
These holes are dug with so much art, that there 
seems the design of an architect in the formation. 
There are usually two apertures, by one of which 
the little inhabitant can always escape, when the 
enemy is in possession of the other. Many crea- 
tures are equally careful of avoiding their enemies, 
by placing a centinel to warn them of the approach 
of danger. These generally perform this duty by 
turns ; and they know how to punish such as have 
neglected their post, or have been unmindful of 
the common safety. Such are a part of the efforts 
that the weaker races of quadrupeds exert to 
avoid their invaders ; and, in general, they are 
attended with success. The arts of instinct are 
most commonly found an overmatch for the in- 
vasions of instinct. Man is the only creature 
against whom all their little tricks cannot prevail. 
Wherever he has spread his dominion, scarce any 
flight can save, or any retreat harbour ; wherever 
he comes, terror seems to follow, and all society 
ceases among the inferior tenants of the plain ; their 
union against him can yield them no protection* 
