germination (jerminashon)

[ The perpetual leaven and germinations , the thrustings forth and swelling of his senses. Jer. Taylor , Works (ed. 1835), II. 12. Specifically, in bot.: ( a ) The proce of development of the embryo of a seed into a perfect plant. The conditions ne ce ary for germination are the presence of moisture, free oxygen, as in atmospheric air, and warmth. Moisture softens the integuments of the seed and relaxes the ti ues of the embryo, at the same time di olving such nutrient matters in the seed as sugar, dextrine, etc., in readine for their a imilation by the embryo. The absorption of oxygen is nece ary for the chemical changes which always accompany growth. The degree of warmth needed to excite to action the vital forces of the plant varies in different species, some as those of wheat, being capa ble of germinating upon melting ice, while others require a temperature of over 60° F. During germination various chemical changes take place in the above ground. starch and other Seeds Germinating. The central figure shows a plant which has newly appeared insoluble material stored up for the use of the embryo in the cotyledons or in the albumen of the seed, rendering them soluble and fit for a imilation, which changes are usually accompanied by an increase of temperature, as is seen in the proce of malting. As an immediate result of the growing proce thus excited and carried on in the seed, a root is produced which strikes downward, fixing itself in the soil and beginning to absorb thence nourishment for the new plant. At the same time the other extremity of the axis of growth is directed upward and develops a stem and leaves. (b) The similar development of a plant from the spore in cryptogams. (c) The early period of growth in a bud, as a or of a rhizome. (d) The protrusion and growth of the pollen-tube from the pollen-grain.