The Vegetable World: Being a History of Plants, with Their Botanical Descriptions and Peculiar Properties

The antherids are small i] cellular mamelons, formed, according to M. Thuret, of

ring-like cellule, is only filled with a greyish granulose matter; by degrees, small sperical bodies are seen, which are the antherozoids, As these develop themselves the central cavity Mereases in volume, and presses strongly upon the walls of the | Peripheric cellule. Finally the time comes when the prosvaxe a -*° Great that the antheridis suddenly burst; the uppermost ee

cellule, which had served as a covercle or lid to the central expelled through the fracturecavity, is broken, or is occasionally at the cuticle (Fig. 346), the antherozoids being expelled at the same time. At the moment of their expulsion the antherozoids present themselves in the form of little greyish spherical vesicles, whose

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Fig. 347.

contents are very indistinct (Fig. 347). At first they are a movable; but after some minutes they begin to unroll themselves suddenly, and dart into the ambient liquid with inconcelv@ rapidity. They now turn themselves with gyratory movemen which are sometimes continued without interruption during gcse and even two hours. If a drop of iodine is added under the microscope, these movements are suddenly arrested. Their body twisted and contorted, forms a sort of spiral ribbon; it is ée imperfectly defined about the extremities. The locomotive ee of these strange bodies consist of bundles of short cils, 2 8*

numbers, forming a sort of crest, which emanates from the anterior

part of the body. The number of these cils is sufficient to account for the extreme rapidity with which these antherozoids move.

These facts overturn all our notions as to the distinctions of animals and plants. Here are simple vegetable organs which seem to have the power of motion; and if we reflect that on the other hand there are animals, as the sponge, corals, and adult oysters, which are altogether immovable, we may well ask which is the plant and which the animal? We can only reply that the distinctions which science is compelled to draw among living beings become impossible when we reach the confines of what is usually designated the two kingdoms of nature.

The female organs of the plants which occupy our attention are less numerous than in the preceding orders; a proembryo does not bear more than from four to twenty (Figs. 346 and Fed, 348). They occupy the lower surface of the ieee prothallium, but in front of the side of the seolated Aihegonium, hollow; each of them presents itself as a rounded cavity, plunging ito the interior of the parenchyma, and communicating with the exterior by a sort of chimney, so to speak, formed by sixteen transparent cells disposed in fours, the one above the others (Fig. 348). We ought to remark here, that the two kinds of organs which have been described may exist at once in the same prothallium as in Fig. 346, or they may be distributed upon several, as in Fig. 344. They are, then, monzceous or disceous. As to the fact of the fecundation, it can no longer be contested. Herr Suminski has seen and figured the antherozoids in the interior of the cavity of the archegonium, and his observations have been confirmed by other observers, Without entering into details respecting the development of ‘© embryo vesicle in the interior of the cavity of the archegone, we may remark that we only see a single plant issue from the pro- — é /0, as if a single archegone had been fertilised, or at least one only takes such a form as to hinder the growth of all others. — on the themselves develop which the capsules ee conclude,

lower surface of the fronds of ferns are not fruit, as has been assumed until lately;nor are the spores enclosed in the capsules seeds. The male and female reproductive organs are developed on a small and transitory cellular apparatus resulting from the germination of the spores.

Cxass IT].—Ru1z0cGens.

The Rihzogs are a most anomalous collection of spores, at once leafless and parasitical. They have the loose cellular organisation of Fungi, traces of a spiral structure among their tissues, with stem and root analogous to the thallus of Fungi, and probably partaking of their singular mode of growth; their flowers ate like more perfect plants, and their sexual organs complete; their embryo, without visible radicle or cotyledons, presenting the appearance of a spherical or oblong homogeneous mass, adding toa fun mode of growth a perfect sexual apparatus. '

( Ovaies solitary, pendulous, one-seeded. XXVI. Balanophorace®. vules parietal, many-seeded, calyx 3, 4, rytinaceee.

RHIZOGENS, |[Brats anthers opening by slits oe EVE. © les parie many-seeded, calyx ya esiacez. parted, anthers opening by pores XXVIII. Ball

They are a singular class of parasitical plants, which have cellular scales instead of leaves, but with true flowers. They agree W’ Exogens in having sexual organs, and with the Fung: ™ the presence of a mycelium, and in their parasitical habits, and m their are leafless root pat The Balanophoracee consistence.fungus-like sites, with flowers, brown, red, white, or yellow, but never greet having underground stems, rhizomes, or tubers, from which ee 8 ee erect simple peduncles. They are found on the roots of the Ni - maple, and oak; abounding in the mountains of tropical countries a America, The Cytinacee are parasitical on the roots of the Cistus Euphorbias of the aeof the south of Europe, and on the succulent are stemless plants of the ap Rafflesiacee Cape of Good Hope. from the surfaces — immediately Indies, the flowers of which spring of the branches, and are immersed among the scales which represe™ ‘ |

leaves.

Crass IV.—EnpocEns, or Monocory.epons.

Endogenous or Monocotyledonous plants are herbaceous, very rarely woody plants; Ruscus aculeatus being the only species with woody fibres indigenous to this country. Schleiden, in describing the peculiarities of Endogens, and the manner in which they differ from Exogens, says that all plants whose development proceeds from the interior to the exterior are either limited or unlimited in their growth. Woody fibre gene-o_ Tally assumes two different physiological phases:. 1, Of an extremely delicate tissue, capable of rapid development, in which new cells are continually generated and deposited in two different directions, as in Fig. 349; namely, next the circumference when the tissue is of a peculiar *} lengthened kind, with thick walls and liber; and next the centre in the form of annular, spiral, teticulate, or porous vessels; 2. Of woody cells, Which form wood properly so-called. Up to a certain point the development of the vascular system is the same, but in Endogens the active skin and delicate cellular tissue suddenly change, the partitions of the cells become thicker, then the Senerating power ceases; and when fully enveloped they assume a peculiar form, cease to convey _ any kind of formative sap, and all further de- ky Veda velopment of vascular bundles becomes impossible, and therefore the production of woody bundles is limited. In Exogens, on the contrary, this tissue retains its vital function during the whole life of the plant. The general characteristics of Endogens are a fructification *Pringing from a stem; wood youngest at the centre; cotyledous ‘ingle leaves parallel, veined, permanent; wood of the stem always sed, and indistinct in its fibre. a.

Endogens consist of 1,420 genera and 13,684 species, whose Setmination is endorhizal, whose embryo has but one cotyledon,

whose leaves have parallel veins, and whose trunk is formed of bundles of spiral and dotted vesicles, guarded by woody tubes, whose bundles are arranged in a confused manner and reproduced in the centre of the trunk. Leaves and stem are here distinctly separated. Spiral vessels, breathing pores, and sexual organs free from complication. The palms may be considered as the typical form of Endogens; the grasses are Endogens with hollow stem. Dr. Lindley divides the class into—

SECTION 1.—FLOWERS GLUMACEOUS, WITH IMBRICATED, COLOURLESS, OR HERBACEOUS SCALES.

SECTION 2.—PETALOID FLOWERS, WITH TWO CALYX OR COROLLA, OR BOTH, NAKED.

SECTION 3.—FLOWERS WITH A TRUE CALYX AND COROLLA ADHERENT TO THE OVARY, UINSEXUAL.

SECTION 4.—FLOWERS WITH TRUE CALYX AND COROLLA FROM THE OVARY.

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The rushes have flowers herbaceous, dry, and permanent, hypogynous, bisexual, scaly, 15. JUNCALS scarious, if coloured; albumen copious;em- LVI. Juncacee i: bryo, minute and undivided in the Rushes; LIX, Orontiacee. : axile with a cleft on one side in the Oron-tiaceez. ( Flowers hexapetaloid, succulent, withering, albumen copious. P: th Aed by a calycine, involucres, inner bracts, co- pee loured, and petaloid in Gilliesiacez, naked | ao Npemo 16, Linrats. 4 and flat when withering; anthers turned L LXII, Lilisces. outward in Melanthaceee, anthers turned LXI. Puntededas iis inward in Liliaces; ianth naked; ci ‘ ey nate anthers turned inwards in Ponte- \deracez. ) Flowers, three, six petalous, hypogynous, with separate carpels, without albumen; sometimes bisexual; many-seeded in Buto- LXTV, Butomacee. 17. ALISMALS, mace; few-seeded, simple, and axial, with LXV, Alismacee. : solid embryo in Alismaceze; flower scaly, LXVI. Juncaginacez. few-seeded, simple, and axial, with large plumula in Juncaginaceex,

GLuUMACEOUS PLANTs.

So called from their flowers being composed of bracts and not collected in whorls, but consisting of imbricated colourless or herbaceous scales. The grasses and sedges of which they consist constitute avery large proportion of the vegetation of the globe, covering our fields with verdure, and furnishing food for man and beast. They are provided with stamens and pistils, which are indispensable to the production of seeds, but there is scarcely a trace of calyx or corolla. is division of Endogens is thus distinguished: the Graminacee by