. A manual of the medical botany of North America [microform]. Botany, Medical; Botany; Botanique médicale; Botanique. THE SEED. 43 the milk-wood, or with nioro doliciito libros, as in (cotton (Fi<^. 05). Somo seeds have an additional covering, more or less exi)andod in i'onn, termed an arillus, or aril; of such character is the mace of nutmeg and the scarlet pulp enclosing the seeds oi the woody bitter-sweet [Cduiitrus scaii- dcns), so nuxch used fov winter decoration. All tlie expansions of the external seed-coat are evidently designed to favor the distribution of the seeds. The scar loft
. A manual of the medical botany of North America [microform]. Botany, Medical; Botany; Botanique médicale; Botanique. THE SEED. 43 the milk-wood, or with nioro doliciito libros, as in (cotton (Fi<^. 05). Somo seeds have an additional covering, more or less exi)andod in i'onn, termed an arillus, or aril; of such character is the mace of nutmeg and the scarlet pulp enclosing the seeds oi the woody bitter-sweet [Cduiitrus scaii- dcns), so nuxch used fov winter decoration. All tlie expansions of the external seed-coat are evidently designed to favor the distribution of the seeds. The scar loft where the seed-stalk separates is termed the hilum ; the minute orifice through which the pollen-tube entered, now closed up, is termed the micropyle. Tlie kernel is tlio essential part of the seed. In many seeds it is all embryo—that is, a minute folded-up plantlet; in others it comprises not. -'".- FlQ. 91.—Winged sccil of tlio pino. Fin. O.'i. — ficed. only the embryo, but a mass of nourishing matter in which this is im- bedded, termed the albumen. The albumen is composed of stai'ch, gluten, oily matters, etc., and is designed to nourish the young plantlet during the early stages of its de- velopment, before its roots have taken firm hold of the soil. It should be borne in mind that this ditVers in every essential particular from animal albumen. The embryo, or germ, is the embryo plantlet whose development we have studied in the bean and Indian corn. It is distinguishable into throe parts, namely, (1) the radicle, called also and more properly the caulicle, or rudimentary stem, to one end of wliioli are attachetl (2) the cotyle- dons, or seed-leaves, between which is the rudimentary bud termed the (3) plumule, while the other end becomes the descending axis. And here we leave this branch of our siibject, having outlined, in a gen- eral way, the history of flowering plants from their germination in the seed to their reproduction in seed again. From this h
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