The grain of wheat is a part of the flower of the wheat plant, which, when it becomes ripe, is easily separated. It contains a minute and rudimentary plant; and, when it is sown, this gradually grows, or becomes =developed= into, the perfect plant, with its stem, roots, leaves and flowers, which again give rise to similar seeds. No mineral body runs through a regular series of changes of form and size and then gives off parts of its substance which take the same course. Mineral bodies present no such =development= and give off no seeds or =germs=. They do not reproduce their kind. 63. =The Living Animal increases in Size by adding to the Substances which compose its Body, like Substances; these, however, are chiefly derived directly from other Animals or from Plants.= The fowl in the farm-yard is incessantly pecking about and swallowing now a grain of corn, and now a fly or a worm. In fact, it is feeding, and, as every one knows, would soon die if not supplied with food. It is also a matter of every day knowledge that it would not be of much use to give a fowl the soil of a cornfield, with plenty of air and water, to eat. In this respect, the fowl is like all other animals; it cannot manufacture the proteid materials of its body, but it has to take them ready made, or in a condition which requires but very slight modification, by devouring the bodies either of other animals or of plants. The animal or vegetable substances devoured are taken into the animal’s stomach; they are there digested or dissolved; and thus they are fitted to be distributed to all parts of the fowl’s own body, and applied to its maintenance and growth. 64. =The Living Animal, after it has grown up, detaches part of its Substance, which has the Power of growing into a similar Animal, as an Egg.= The fowl’s egg is formed in the body of the hen, and is, in fact, part of her body inclosed in a shell and detached. It contains a minute rudiment of a fowl; and when it is kept at a proper temperature by the hen’s sitting upon it, or otherwise, for three weeks, this rudiment grows or develops, at the expense of the materials contained in the yolk and the white, into a small bird, the chick, which is then hatched and grows into a fowl. The animal, therefore, is produced by the development of a germ in the same way as the plant; and, in this respect, all plants and all animals agree with one another and differ from all mineral matter. 65. =Living Bodies differ from Mineral Bodies in their Essential Composition, in the manner of their Growth, and in the fact that they are reproduced by Germs.=