[389.] Its Radicle or Caulicle (the former is the term long and generally used in botanical descriptions, but the latter is the more correct one, for it is the initial stem, which merely gives origin to the root), as to its position in the seed, always points to and lies near the micropyle. In relation to the pericarp it is
Superior, when it points to the apex of the fruit or cell, and
Inferior, when it points to its base, or downward.
Fig. 424. Embryo of Calycanthus; upper part cut away, to show the convolute cotyledons.
[390.] The Cotyledons have already been illustrated as respects their number,—giving the important distinction of Dicotyledonous, Polycotyledonous and Monocotyledonous embryos ([36-43]),—also as regards their thickness, whether foliaceous or fleshy; and some of the very various shapes and adaptations to the seed have been figured. They may be straight, or folded, or rolled up. In the latter case the cotyledons may be rolled up as it were from one margin, as in Calycanthus (Fig. [424]), or from apex to base in a flat spiral, or they may be both folded (plicate) and rolled up (convolute), as in Sugar Maple (Fig. [11].) In one very natural family, the Cruciferæ, two different modes prevail in the way the two cotyledons are brought round against the radicle. In one series they are
Accumbent, that is, the edges of the flat cotyledons lie against the radicle, as in Fig. [425, 426]. In another they are