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tled to the name ; for the pulp is not properly a part of the fruit, but originates from some other organ.
In the mulberry and strawberry the calyx becomes coloured and very juicy, surrounded by seeds like a real berry. Some botanists, in describing the strawberry, say that what is commonly called the berry, is but a pulpy receptacle, studded with naked seeds. In the figf the whole fruit is a juicy calyx, or common receptacle, containing in its cavity innumerable flo. rets, each of which has a proper calyx of its own, which becomes pulpy, and invests the seed, as in the mulberry. The paper mulberry of China, which is analogous to it, is an intermediate genus between the two, being, as it might seem, a fig laid
open, but without any pulp in the common receptacle. 9th. STROBILUM, a cone, is a catkin or ament hardened and enlarged into a seed vessel, as in the pine; this is called an aggregate, or compound pericarp. In the most perfect examples of this kind of fruit the seeds are closely enveloped by the scales as by a capsule. The Strobilum is oblong in the pine, round in the cypress, very small in the alder and birch.Ş The time for examining fruits is after the flowers have pass
you have understood the simple division of fruits we have now given, you will not be at a loss to which of these classes to refer them, when you see an apple, a walnut, a currant, or a pine apple. You may gratify the mental appetite by examining their scientific characters. It would seem more rational for young persons to examine the number of cells or seeds in an apple, with a view to a classical arrangement, than to count the seeds with the foolish idea that there is some charm in a certain number, which will throw light upon their future destiny.
The Seed. We have now traced the plant, from the root through all its various organs, until we have arrived at that part, which is a link in the chain of vegetable existence, connecting the old and new plant; if this were destroyed, if the seeds of plants were no longer perfected, what changes would the whole face of nature present! The earth in one year would be stripped of the whole tribe of annual plants; in another the biennial plants
* See genus Bacca, order 7th of the class Gymnocarps. + See genus Sorose, in the class Angiocarps.
See genus Sycone, of the class Angiocarps $ See
genus Strobilum, of the class Angiocarps. Strobilum-Proper time for examining fruits-Appearances which nature would present if the seed were no longer perfected.
would vanish, leaving a still more cheerless vacancy; the pe. rennial would, year after year, disappear, until (if we could suppose our own lives to be prolonged in such a strange state of nature,) we should behold the earth one vast scene of vegetable ruin; occasionally here and there a venerable oak or an an. cient pine would stand in solitary grandeur, the mournful remnants of a once beautiful and fertile vegetable kingdom.
But such a sad spectacle the earth will never present, for we have the promise of God himself, that “while the earth remaineth, seed time and harvest shall not cease.
We have seen, in the progress of our enquiries, that while the present plant is diffusing around it beauty and fragrance, ad. ministering to the necessities and luxuries of man, the watchful care of that Being who never slumbers nor sleeps, is by a slow, but certain progress, perfecting that part which is destined to continue the species, and which is, 6 the sole end and aim of all the organs of fructification."*
The seed is that internal part of the fruit which envelopes the complete rudiment of a new plant, similar to that from which it received its existence. Seeds are various in their
the mustard is globular; some species of beans are oblong; the cocoa nut is ovoid; the buck wheat is angular, &c. The seed consists of three principal parts, viz. the
husk and kernel.
1st. The eye or hilum is the scar formed by the separation of the membrane or thread which connected the seed with the pericarp, and conveyed to the former the necessary nourishment. This connecting membrane is usually very short; but in the magnolia and some other plants it is several inches in length. When the seed is fully ripe, the connexion between it and the pericarp, ceases by the withering and separation of the connecting membrane, leaving upon the outer surface of the seed, the mark of its insertion. This eye or scar is very conspicuous in Fig. 84.
the bean, which also exhibits the pore through which the nourishment was con. veyed to the internal parts of the seed. That part of the seed which contains the eye is called the base; the part opposite, is called the apex.
Fig. 84 represents the garden bean; it is an oblong, tunicated seed ; between its two thick cotyledons; at a, may be seen the hilum.
* Linnæus. Seed contains the rudiment of a new plant-Forms of seeds-Parts of the seed-Eye.
2d. The Husk, is the outer coat of the seed which, on boil. ing, becomes separate; as in peas, beans, Indian corn, &c.; this skin is also called the spermoderm from the Greek words, sperma, signifying seed, and derma skin. The spermoderm or skin of the seed consists of three coats, analogous to the three divisions of the pericarp; the external skin, called the testa or cuticle corresponds to the epicarp or outer covering of the pericarp; the cellular tissue called mesosperm, corresponds to the mesocarp, or middle of the pericarp; and the internal skin or endosperm corresponds to the endocarp or inside skin of the pericarp. *
The husk surrounds the kernel ; it is essential, as the kernel which was originally a fluid, could not have been formed without its presence.
3d. The Kernel, includes all that is contained within the husk or spermoderm ; it is also called the neucleus or almond of the seed. The kernel is usually composed of the albumen, cotyledon and embryo. The Albumen is that part of the kernel which invests the cotyledons or lobes, and is thought to afford the same support to the germinating embryo, that the white of an egg does to a chicken. Both in respect to hardness and colour, the albumen in many seeds greatly resembles the white of a boiled egg. It is not considered an essential 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. 85.
Fig. 8 represents the same seed (the garden bean) as seen at fig. 84; it here shews the cotyledons as divested of the husk ; a represents the cotyledons ; and c, the embryo; d shews the petioles
or stems of the cotyledons. d
Cotyledons (from a Greek word, kotule, a cavity), are the thick fleshy lobes of seeds, which contain the ernbryo. In
beans they grow out of the ground in * These three divisions may not always seem distinct, as in some cases,
the mesosperm is scarcely to be separated from the cuticle.
Husk-Spermoderm, divisions-Cuticle-Mesosperm—Endosperm-Husk ssential -Kernel, of what composed ?-Albumen-Cotyledons.
the form of two large leaves. Cotyledons are the first visible leaves in all seeds, almost always fleshy and spongy, of a succulent and nourishing substance, 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. The number of cotyledons varies in different plants, and there are some plants which have
Acotyledons, are those plants which have no cotyledons in their seeds; such as the cryptogamous plants, mosses, &c.
Mono-cotyledons, such as have one cotyledon or lobe in the seed; as the grasses, the liliaceous plants, &c.
Di-cotyledons, such plants as have two cotyledons: they include the greatest proportion of vegetables; as the leguminous, the syngenesious, &c.
Poly-cotyledons, those plants the seeds of which have more than two lobes: the number of these is small; the hemlock and the pine are examples.
The number of cotyledons seldom varies in the same family of plants : it has 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 number, it is necessary to examine the seed in a germinating state ; this is often difficult. The natural method of Jussieu is founded upon the number of cotyledons.
The Embryo, is the most important part of the seed, as it forms the new plant; all other parts seem but subservient to this. The embryo has been called the Corculum, or heart : it is the point from whence the life and organization of the fu. ture plant originate. In most dicotyledonous seeds, as the bean, orange and apple, the embryo may be plainly discovered. Its internal structure, before it begins to vegetate, is very simple, consisting of a uniform substance, enclosed in its appro. priate bark or skin. When the vital principle is excited to action, vessels are formed, and parts developed, which seemed not previously to have existed. The embryo is usually central and enclosed by the cotyledons : sometimes it is no more than a mere point or dot, and in some cases, altogether invisible to the naked eye. The embryo consists of two parts.
The Plume, which is the ascending part, unfolding itself into herbage.
What are Acotyledons ?-Monocotyledons ? - Dicotyledons ?-Polycotyledons ?-Number of cotyledons made the basis of classification-Embryo-Di-' visions of the embryo.
The Radicle, or descending part, which b
unfolds itself into roots. At Fig. 86 appears the embryo in a germinating state; a represents the radicle, b the plume, c the cord by which the plant is still con. nected to the cotyledons, and receives from them its nourishment.
To use the words of an ancient botanist, “the embryo continues imprisoned within its seed, and remains in a profound sleep, until awakened by germination; it meets the light and air to grow into a
plant, similar to its parent.
And boundless forests slumber in a shell."* There are various appendages which may, or may not be present without injury to the structure of the seed.
Aigrette, or egret, sometimes called pappus, is a kind of feathery crown with which many of the compound flowers are furnished, evidently for the purpose of disseminating the seed to a considerable distance by means of winds; as the dandelion. It includes all that remains on the top of the seed after the corolla is removed.
Stipe is a thread connecting the egret with the seed. The egret is said to be sessile when it has no stipe, simple when it consists of a bundle of hairs without branches, plumose when each hair has other little hairs arranged along its sides, like
* These lines, which so beautifully set forth the manner in which the embryo is contained within the seed or bulb, are not entirely philosophical as to the fact of the future generations lying enfolded, the one within the other; it is true, that we may in many seeds, by the help of a microscope, discern the form of the future plant, and even the embryo flower ; but we cannot believe that, in the seed of that embryo flower, is the miniature image of another plant, which contains another, and so on through successive generations; for the fact is established that a seed does not produce a plant without being fertilized by the pollen. We may say that a seed contains within itself the elements of future generations ; but not their images, except that of the immediate plant which is to issue from the perfected seed.
Appendages to seeds—Egret—Stipe.