CLASSIFICATION OF ANIMALS. 237 



as follows : — " Yertebral animals, having backbones : Aver- 

 TEBRAL ANIMALS, destitute of backboiies. Vertebral animals 

 are divided into, 1. Quadrupeds ; — the science of which has no 

 popular name ; it includes four-footed animals, as ox, dog, 

 mouse. 2. Birds ; — the science of which is called ornitholofjy ; 

 it includes the feathered triBe, as pigeon, goose, wren. 3. Am- 

 phihioiis Animals ; — the science of which is called amjyhihiolo- 

 gy ; it includes those cold-blooded animals wdiich are capable 

 of living on dry land, or in the water, as tortoise, lizard, serpent, 

 frog. 4. Fishes ; — the science of which is called ichthyology ; 

 it includes all aquatic animals which have gills and tins ; as 

 shad, trout, sturgeon, eel. Avertebral animals are divided 

 into, 5. Insects ; — the science of which is called entomology ; it 

 includes all animals with jointed bodies, which have jointed 

 limbs, as flies, spiders, lobsters. 6. Vermes; — the science of 

 which is called helminthology ; it includes all soft animals of 

 the avertebral division, which have no jointed limbs, w^ith or 

 without hard coverings, as angle-worms, snails, oysters, polypi, 

 and infusory animals." 



377. Zoophytes^ of animal plants, bring us to the lowest beings 

 in the animal kingdom. Some of the orders of this • class con- 

 tain animals which have neither heart, brains, nerves, nor any 

 apparent means of breathing. These are sometimes called ani- 

 mal plants ; many of them, as the corals^ are fixed to rocks, 

 and change place. The term coral includes under it many spe- 

 cies ; the red coral used for ornaments is the most beautiful. 

 The substance of coral, when subjected to chemical analysis is 

 found to consist chiefly of carbonate of lime ; the hard crust 

 which envelops the animal substance is an excretion formed by 

 it in the same way as the shells of the oyster and lobster are 

 produced, or as nails grow upon the fingers and toes of the hu- 

 man body. The quantity of this carbonate of lime elaborated 

 by the little coral animal is truly wonderful ; islands are formed, 

 and harbors blocked ujd by it. Fig. 165, a^ represents a branch- 

 ing coral ; the dots show tlie apertures by which the animal re- 

 ceives its nourishment. Some of the zoophytes are fixed by a 

 kind of root to the bottom of the sea ; some, as the sea-nettle^ 

 which appears like the segment of a circle, are carried about by 

 the motion of the waters, without any voluntary motion, as are 

 also the sea-daisy^ sea-marigold^ and the sea-carnation^ so named 

 from an apparent resemblance to those plants. We find here 

 the sea-fan^ the sea-pen^ and the madrepore^ the latter of which 

 are often thrown together in vast quantities. 



378. The sponge also belongs to this class of animal sub- 



376. Division of animals into two classes — How many classes of Vertebral animals ?— How are Aver- 

 tehral animals divided ?— 377. Description of zoophyt«s— Corals— Various kinds of zoophytes.— 378. 

 Sponge. 



