lk, or from the placenta when there is
no seed-stalk.

[Illustration: Fig. 418. Seed of White Water Lily, enclosed in its
aril.]

384. A short and thickish appendage at or close to the hilum in certain
seeds is called a CARUNCLE or STROPHIOLE (Fig. 419).

[Illustration: Fig. 419. Seed of Ricinus or Castor oil plant, with
caruncle.]

385. The various terms which define the position or direction of the
ovule (erect, ascending, etc.) apply equally to the seed: so also the
terms anatropous, orthotropous, campylotropous, etc., as already defined
(320, 321), and such terms as

HILUM, or _Scar_ left where the seed-stalk or funiculus falls away, or
where the seed was attached directly to the placenta when there is no
seed-stalk.

RHAPHE, the line or ridge which runs from the hilum to the chalaza in
anatropous and amphitropous seeds.

CHALAZA, the place where the seed-coats and the kernel or nucleus are
organically connected,--at the hilum in orthotropous and campylotropous
seeds, at the extremity of the rhaphe or tip of the seed in other kinds.

MICROPYLE, answering to the _Foramen_ or orifice of the ovule. Compare
the accompanying figures and those of the ovules, Fig. 341-355.

[Illustration: Fig. 420. Seed of a Violet (anatropous): _a_, hilum;
_b_, rhaphe; _c_, chalaza.]

[Illustration: Fig. 421. Seed of a Larkspur (also anatropous); the parts
lettered as in the last.]

[Illustration: Fig. 422. The same, cut through lengthwise: _a_, the
hilum; _c_, chalaza; _d_, outer seed coat; _e_, inner seed-coat; _f_,
the albumen; _g_, the minute embryo.]

[Illustration: Fig. 423. Seed of a St. John's-wort, divided lengthwise;
here the whole kernel is embryo.]

386. =The Kernel, or Nucleus=, is the whole body of the seed within the
coats. In many seeds the kernel is all _Embryo_; in others a large part
of it is the _Albumen_. For example, in Fig. 423, it is wholly embryo;
in Fig. 422, all but the small speck (_g_) is albumen.

387. =The Albumen or Endosperm= of the seed is sufficiently
characterized and its office explained in Sect. III., 31-35.

388. =The Embryo= or _Germ_, which is the rudimentary plantlet and the
final result of blossoming, and its development in germination have been
extensively illustrated in Sections II. and III. Its essential parts are
the _Radicle_ and the _Cotyledons_.

389. =Its Radicle or Caulicle= (the former is the term long and
generally used in botanical descriptions, but the latter is