DURATION OF LIFE.
1489. The age of a plant is included between the the limits of the sap's impulse, and that which has been called its fall or descent.
1490. The actual fall of the sap is the death of the plant.
1491. If with the cessation of the influence of light, the polarity ceases entirely in the plant; it is then one year old or an annual. Every part of it dies off.
1492. In biennial plants the aerial polarity indeed disappears, but the polarity of the root remains. Flower, leaf, and stalk die.
1493. Perennial plants, also, do not entirely lose the stem-polarity, but only while they develop a new plant about the old. Flower and leaf only perish, while the water-and earth-organs remain alive.
1494. The old liber dies with every maturation of the fruit, because there the difference attains solution. But a new life develops itself in the parenchyma of the plant, and forms new liber or, properly speaking, a new plant about the old.
1495. Persistent plants consist of numerous plants, which gradually grow round about each other.
1496. In accordance with the idea of the plant, each one perishes with the maturation of the fruit.
1497. On account of the addition of the new plant about the old, the plant has also been confined to no definite magnitude and to no definite number in its mode of ramification.