INTRODUCTION. ON contemplating, even for a moment, the number of natural objects that almost daily come under our observation, we are struck with wonder and delight at their vastness and variety; and seeing that it has been stated by Ehrenberg that one single cubic line of water (less than a drop), is capable of containing 500,000,000 living Monads, and since the extent of space is unknown and indefinable-well may we exclaim that "it is impossible for the finite to comprehend the infinite." Every object in this world is either animate or inanimate, hence, two grand primary divisions of natural objects have been made, viz., the Organic or living world, and the Inorganic or dead. The study of organic matter is termed Biology (Bios, life; and Moyos, an account of), and includes the departments of Zoology and Botany, while that of inorganic matter includes the departments of Geology, Mineralogy, Chemistry, and Physics. Three kingdoms in nature have been described, viz., the Animal, the Vegetable, and the Mineral. They are briefly defined by Linnæus in the following terse sentences :-The Animal, "Corpora organisita, et viva et sententia, sponteque se moventia;" the Vegetable, "Corpora |