99 SEED. 



The kernel is usually composed of the albumen^ cotyledon, and 

 embryo. 



The Avoumen is that part of tlie kernel which invests the cotyle- 

 dons or iooes, and is thought to afford the same support to the germ- 

 inating ernoryo, that the white of an egg does to a chicken. Both 

 in respecr to hardness and colour, the albumen, in many seeds, greatly 

 resembles the white of a boiled egg. It is not considered an'esseii- 

 tial part of the seed, because it is sometimes wanting ; but when 

 present, it supports and defends the embryo while imprisoned in the 

 seed, and serves for nutriment when it begins to germinate. It has 

 no connexion with the embryo, and is always so distinct as to be 

 easily detached from it. Albumen makes up the chief part of some 

 seeds, as the grasses, corn, &c.; in the nutmeg, which has very 

 small cotyledons, it is remarkable for its variegated appearance and 

 aromatic quality. It chiefly abounds in plants which are furnished 

 with but one cotyledon. 



Fig. 110 represents the cotyledons of the bean, 

 as divested of the husk ; a, represents the cotyle- 

 dons ; b and c, the embryo ; d, shows the petioles 

 or stems of the cotyledons. 



Cotyledons, (from a Greek word, kotule, a cavi- 

 ty,) are the thick, fleshy lobes of seeds, which 

 contain the embryo. In beans they grow out of 

 the ground in the form of two large leaves, h^hey 

 are the first visible leaves in all seeds, often fleshy 

 and spong3^, of a succulent and nourishing sub- 

 stance, which serves for the food of the embryo at 

 the moment of its germinating. Nature seems to 

 have provided the cotyledons to nourish the plant 

 in its tender infancy. After seeing their young charge sufficiently 

 vigorous to sustain life without their assistance, the cotyledons in 

 most plants wither and die. Their number varies in different plants, 

 and there are some plants which have none. 



Acotyledon.^, are those plants which have no cotyledons in their 

 seeds ; such as the cryptogamous plants, mosses, &c. 



Mono-c':^yledons, are such as have but one cotyledon or lobe in the 

 seed ; as ♦.he grasses, the liliaceous plants, &c. 



Di-cotyledons, are such plants as have two cotyledons ; they in- 

 clude the greatest proportion of vegetables ; as the leguminous, the 

 syngenesious, &c. 



Poly-cotvledons, are those plants the seeds of which have more 

 than two lobes ; the number of these is small ; the hemlock and the 

 fine are examples. 



The number of cotyledons seldom varies in the same family of 

 plants ; it nas therefore been assumed by some botanists as the basis 

 of classification; but there are difficulties attending a method wholly 

 dependant on these organs. In order to be certain as to their num- 

 ber, it is necessary to examine the seed in a germinating state ; this 

 is often difficult. The natural method of Jussieu is in part founded 

 upon the number of cotyledons. 



The Embryo is the most important part of the seed ; all other parts 

 seem but subservient to this, which is the point from whence the life 

 and organization of the future plant originate. In most dicotyledo- 



Albumen— Describe Pig. 110— Cotyledons— What plants are called Acotyledons? 

 —What Monocotyledons7—What Dicotyledons?— Polycotyledons7— Why is the 

 number of cciyledons made the basis of classification— Embryo. 



