48 BOOK OF NATURE LAID OPEN. 



the bottorr of the river. This n.ight bring us to 

 speak more fully of those particular instincts by 

 which animals are distinguished ; but as we shall 

 have occasion to notice a few of these in considering 

 some peculiarities in the difterent orders as we go 

 along, we will here drop the general survey, and 

 proceed to that of 



Quadrupeds. 



OF this order it may be remarked in general, that 

 they derive their name from the number of their 

 legs ; and this naturally occasions in those that make 

 use of them for the purpose of walking, the prone 

 posture by which they are distinguished ; but this 

 posture, far from incommoding them, is, by the wise 

 conformation of the other parts, rendered the most 

 commodious possible for their habits and manner of 

 living. Quadrupeds are, for the most part, furnish- 

 ed with tails, and these are highly useful in the 

 absence of arms, for sweeping off vermin and trou- 

 blesome animals. Having no hands to lift their 

 food to their mouths, the necks of this order are in 

 general proportioned to the length of their fore legs; 

 their legs are made to bend in such a direction as 

 with the greatest ease to facilitate their motion for- 

 wards ; they have, for the most part 7 a covering of 

 hair or wool ; and, that the weight of the head 

 might not become too heavy in the act of feeding, 

 each of these animals is furnished with a strong 

 tendinous insensible ligament, braced from the head 



