CHAPTER II. 







DIVISION OF THE ANIMAL KINGDOM. 



1. CUVIEE has divided animals into four great groups. 

 1. The vertebral. 2. The molluscous. 3. The articulated. 

 4. The radiated. The three last are destitute of vertebrae, 

 or a connected series of bones to form a spinal column. 

 They are, therefore, called invertebrated, while the term 

 vertebrated is applied to the former. The vertebral are 

 again divided into four classes, viz. 1. Mammalia. 2. Birds. 

 3. Reptiles. 4. Fishes. These are also distinguished by 

 the terms warm, and cold-blooded ; the warm-blooded, in- 

 cluding the two former, which possess a temperature con- 

 siderably above that in which they live ; while the two 

 latter, or the cold-blooded animals, are but little warmer 

 than that of the medium by which they are surrounded. 

 The mammalia are divided into nine orders ; Birds into 

 six ; while Reptiles include Tortoises, Lizards, Serpents, 

 and Frogs. Fishes are divided into the Cartilaginous and 

 Bony. 



2. Molluscous animals, as the name signifies, are. those 

 which have no bones corresponding to those of the higher 

 orders of animals. They include all those animals with soft 

 bodies, which dwell in calcareous habitations, constructed by 

 themselves ; many of them are accordingly called shell-fish, 

 such as the oyster, muscle, clam, &c. This division also 

 embraces the snail, slug, and the nautilus. The articulated 

 class includes such animals as are furnished with joints, 

 with a hard external crust, or skeleton, to which are attach- 

 ed the organs of motion. It embraces the annelides, or red- 

 blooded worms, the Crustacea, (the lobster and crab,) Spiders, 

 and Insects. The Radiated class includes the Zoophytes, or 

 Plant animals, so called from their resemblance to the veget- 



