Seed
consists essentially of the young plant or embryo, inclosed in integuments, of which there are usually two.
It varies much in form. The outer integor episperm. It is usually of a brown or ument, or seed coat, is termed the testa somewhat similar hue, but it frequently assumes other colors. The inner integuis called the tegmen, or endospleura; it is generally of a soft and delicate nature . A third integument, more or less complete, is occasion tion of the seed, called the nucleus, or the surface of the others. The inner poroccasionally found on kernel, may either consist of the embryo SEEDING alone, as in the wallflower and the bean, or of the embryo inclosed in albumen or perisperm, as in the morning-glory.
When the nourishing matter, called albumen, is present, the seed is said to be albuminous; when it is absent, to be exalbuminous. The duration of the vitality of seeds is a much discussed question.
Few seeds germinate after three or four years. See ALBUMEN: EMBRYO: OVARY:
PLACENTA.