FIRST DIVISION 



OF 



THE LIVING WORL 



VERTEBRAL ANIMALS. 



A EEiiArLKAELE analogy is perceptible in the organization and strnctnrc 

 of all the classes and orders of this division. The spinal or vertebral 

 cohunn, which consists of a series of bones, articulated or bound together, 

 extends through the whole body, at the back, furnisliing a support for all 

 its parts. The upper extremity is crowned with the head, and the lower 

 terminates in the pelvis, or a tail. This bony column contains the spinal 

 marrow, where the organs of sensation — the nerves — have their origin, 

 and from which they diverge. The principal organs of life are contained 

 in the chest and abdomen. Animals of tiiis division consist of two sexes, 

 male and female. A liver, spleen, pancreas, jaws incumbent, transversal, 

 and furnished with teeth, — rudiments of teeth are seen in the beaks of 

 birds, — and limbs, not exceeding four, form the principal features which 

 mark the character of vertebrate animals. 



FIRST CLASS OF VERTEBRAL ANIilALS. 

 ]\Iammall\. 



Animals of this class bring forth their young alive ; nourish them by 

 teats ; have a heart with two ventricles ; lungs ; a convoluted brain ; five 

 senses; a muscular diaphragm, between the chest and abdomen; warm 

 blood and seven cervical vertebral Tiiev are divided into orders, based on 

 the varied structure of their hands or feet, and teeth, as tliesc organs 

 indicate more fully than any others their habits and mode of life. 



" This class," says Baron Cuvier, " deserves to be placed at the head of 

 the animal kingdom, because we ourselves belong to it, and also because 

 it is that which is endowed with the most various powers, most numerous 

 faculties, and delicate sensations, — all which combine to produce a higher 



(5) 



