iv INTRODUCTION, 



V 



THE ANIMAL KINGDOM. 



THESE words are expressive of one of the three great divisions of material substances ; 

 namely, all those that are possessed of animal life? as distinguished from plants, which have 

 vegetable life, and from minerals, which are understood to hare no life of any kind. In what 

 we are accustomed to call the more perfect instances of them, the distinguishing characters 

 of all tfiV three are so clear and explicit, that nobody has the least hesitation or difficulty in 

 discriminating them ; and thus they neither need nor admit of explanation. They belong to 

 that department of knowledge in which words can add nothing to the information derived 

 immediately from the senses ; and, therefore, in proportion as attempted definition becomes 

 more elaborate, it also becomes more inapplicable. When, however, ^the characters have 

 a certain degree of obscurity, and one part of the subject belongs, or appears to belong, 

 more to one division, and another part more to another division, it then becomes 

 rather puzzling to decide, and popular judgment assigns the subject to that division 

 of which it has the external characteristics most conspicuously. With the products of 

 the land there is little difficulty ; for though the forms of some plants, or parts of plants, 

 have a slight resemblance in shape, and occasionally in colour, to animals as, for instance, 

 the flowers of some species of orchis to insects, and the fruit of some cucumbers to 

 snakes, yet in these as in all other cases of land plants, there are always accompanying 

 parts or circumstances, which prevent the possibility of mistake ; and the observer can 

 admire the resemblance, just as he would admire a picture, without any danger of confound- 

 ing the identity. Farther, as the food of animals does not come regularly in the air, 

 all land animals are, to some extent or other, locomotive, and none of them are rooted. 

 We know less of the food of plants than of that of animals ; but it is probable that all 

 plants feed in part upon air, or, which amounts to the same, upon air-borne substances ; 

 and, therefore, though all plants are not rooted in the earth, none of them are locomotive. 

 The common sensitive plant, and the various other plants, the leaves and other parts of 

 which move when touched, do not indicate the least approach to the animal character. 

 Growth from the end, drooping in the heat, erection of the leaves during a shower, are 

 motions common to most plants ; and the plants alluded to are merely instances of some of 

 the more singular modifications of the common vegetable motion. 



In the waters it is different ; and though, even there, there is no danger that a plant 

 shall be mistaken for an animal, or that the whole of an animal (when known) shall be 

 mistaken for a plant, yet there are cases, in which, from our ignorance of the whole, we are 

 in some danger of mistaking part of an animal for a vegetable, or even for a mineral. 

 The water, by its natural currents, and also by the smaller currents, which many of its 

 inhabitants are capable of producing, brings their food to many of those inhabitants, just as 

 the air does to plants upon land. And of the species which are fed in this way, which are 

 often very minute, there are many that are elevated upon stems or pedicles, and these are 

 so plant-like in their forms, that they have sometimes been regarded as plants ; and 

 writers on vegetables have claimed the sponges, corals, and corallines, as members of 

 the vegetable kingdom. On the other hand, the supports of some of these aquatic animals 

 take so much the form, and acquire so much the consistency, of rocks, (as in the small 

 animals which form coral reefs with such wonderful rapidity in some seas,) that they have 

 sometimes been considered as minerals. But a very little observation enables us to make the 

 distinction, even in those cases in which it appears to be most obscure. The hard parts of 

 animals generally burn into lime (though in some of the obscurer aquatic ones there is silex), 

 or we can detect lime in them by chemical tests ; and in the progress of burning, they all, 

 more or less, give out an ammoniacal smell, that smell which is so powerfully given out in 



