Cuvierian System of Zoology, 129 



Vertebrated animals form the most important division of the 

 animal kingdom. Their bodies and limbs being supported by a 

 framework {charpente) or skeleton, composed of pieces which 

 are connected or movable ; their motions have more strength 

 and precision than those of animals in the other divisions, and 

 the solidity of their supports permits them to attain a great 

 size: the largest animals are found in this division. The 

 nervous system of vertebrated animals being more concen- 

 trated, and the central mass or brain more voluminous, than in 

 animals in the other three divisions, their sensations {sentz- 

 mens) have more energy and duration, hence they possess 

 superior intelligence and greater perfectability. 



The body of vertebrated animals is composed of a head, a 

 trunk, and limbs. 



The head is formed of the skull which encloses the brain, 

 and of the face which is composed of two jaws, and the recep- 

 tacles of the organs of sense. The trunk is supported by the 

 backbone and the ribs. 



The backbone, or spine, is composed of numerous bones 

 called vertebrae, moving upon each other ; the first supports 

 the head. All the vertebrae are perforated, and together they 

 form a bony channel or tube, in which is lodged that trunk of 

 the nervous system called the spinal marrow. 



The backbone is most frequently prolonged beyond the 

 lower limbs, and forms a tail. 



The ribs are semicircles, which protect the sides of the 

 cavity of the body ; most frequently they are articulated at one 

 end to the vertebrae, and at the other to the breastbone or 

 sternum ; sometimes they are scarcely visible. 



Vertebrated animals have never more than two pair of 

 limbs ; sometimes the hind limbs, and sometimes the fore limbs, 

 and sometimes both pairs are wanting, and take other forms 

 relating to the motions they have to perform. The fore limbs 

 may be converted into hands, or feet, or legs, or fins ; the hind 

 limbs into feet or fins. - - 



The blood of vertebrated animals is always red, and has a 

 composition proper to maintain the energy of feeling, and the 

 muscular vigour which exist in different degrees in' the ani- 

 mals belonging to this division, and which correspond with 

 the quantity of respiration. . -. 



The organs of the external senses are always two eyes, two 

 ears, two nostrils, the teguments or covering of the tongue, 

 and those of the whole body. There are always two jaws: the 

 principal motion is in the lower, which rises and falls ; the upper 

 is sometimes entirely fixed. Both jaws are most frequently 

 armed with teeth, excrescenqes of a peculiar nature^ very 



