Animal

All natural things have been recognized as be. longing to one of three kingdoms, the Mineral, Vegetable, or Animal. A little study has shown us that there is a profound distinction between living and inanimate things, that plants and animals are e entially governed by similar laws in their growth and being, and that the substance (living matter or protoplasm) which composes the active part of their structure is, as far as our physical and chemical tests go, incapable of distinction. In defining an animal as distinguished from a plant, we must take a general survey of many features, and each statement will require qualification by exceptions. Animals ultimately depend for food upon the materials manufactured by the aid of chlorophyl, which is almost the exclusive property of a large part of the vegetable kingdom. Animals also as a rule actively seek their food, and are hence gifted with more acute sensation and have locomotor organs, a nervous system, sense, and digestive organs. Many of the lower animals (sponges, hydroids, sea lilies, etc.) resemble vegetables so far in external features as to deceive all but the scientific observer. There are about half a million species of animals, of which about half are insects. See BIOLOGY, PROTOPLASM, ANIMAL KINGDOM.