In plants, Embryo, the embryo, or germ, is the most essential of all, to 
which the rest are wholly subservient, and without which no seed is perfect, 
or capable of vegetation, however complete in external appearance. Lin¬ 
naeus, after Csesalpinus, names it the Corculum , or Little Heart; and it is 
the point whence the life and organization of the future plant originate, as 
we have already explained, p. 96 . In some seeds it is much more conspi¬ 
cuous than in others. The Walnut, the Bean, Pea , Lupine , &c. show the 
embryo in perfection. Its internal structure, before it begins to vegetate, is 
observed by Gsertner to be remarkably simple, consisting of an uniform me¬ 
dullary substance, enclosed in its appropriate bark or skin. Vessels are formed 
as soon as the vital principle is excited into action, and parts are then developed 
which |gemed not previously to exist, just as in the egg of a bird. In position, 
the embryo is, with respect to the base of the whole flower or fruit, either 
erect , as in the Dandelion and other compound flowers; reversed , as in the 
umbelliferous tribe; or horizontal, as in the Date Palm . In situation it is 
most commonly within the substance of the seed, and either central, as in 
■umbelliferous plants, or eccentric, out of the centre, as in Coffee ; in Grasses , 
however, it is external . Its direction is either straight, curved, or even 
spiral, in various instances. The embryo of seeds that have a single cotyledon 3 
or none at all, is peculiarly simple, without any notch or lobe, and is named 
by Gsertner Embryo monocotyledoneus. 
Co tyleboxes, the cotyledons or seed-lobes, are immediately attached 
to the embryo, of which they form, properly speaking, a part. They are 
commonly two in number; but in Pinus, and Dombeya, the Norfolk Island 
Pine, they are more, as already mentioned, p. 98 . When the seed has suffi¬ 
ciently established its root, these generally rise out of the ground, and become 
a kind of leaves. Such is the true idea of the organs in question, but the 
same name is commonly given to the body of the seed in the Grass and 
Corn tribe, the Palms, and several other plants, thence denominated nionoco - 
tyledones , because the supposed cotyledon is single. The nature of this part 
we shall presently explain. It neither rises out of the ground, nor performs 
the proper functions of a cotyledon, for what these plants produce is, from 
the first, a real leaf; or, if the plant has no leaves, the rudiment of a stem, 
as in Cuscuta. In either case, the part produced is solitary, never in pairs; 
hence Grertner was led to reckon Cyamus JVelumbo, Exot . Bot. t. 31, 32, 
among the monocotyledonous plants, the body of its seed remaining in the 
