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

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Fig. 317.—Transverse section of the Conceptacle enclosing Sphores.

the microscope in a drop of sea-water, it is seen that it is entirely fomposed of antherids, which almost immediately discharge the antherozoids which they contain. These move about with the utmost activity, and their movements are prolonged sometimes till the next day, diminishing in their intensity, however, and by the . day at latest they have become decomposed. |

‘Tn order to fecundate the spores and prepare them for germi-hation, it is necessary to mix them with the water which contains Some antherids, If the experiment is made upon a glass plate, and the antherozoids are present in considerable quantities, one of oo curious spectacles which the study of these interesting ne tan. produce will be presented to the observer. The ozoids, attaching themselves in great numbers to the spores, Communicate to them, by means of their vibratile cilie, a move- Ment of Totation, sometimes very ai Sometimes the entire field -:

of the microscope is covered with these thick brownish spheres, bristling with antherozoids, which roll themselves about in all directions, surrounded with swarms of these corpuscles. “In about half an hour, rarely longer, this movement of the spores ceases; the antherozoids continue, however, to be agitated for some time, but with diminished activity, until all movement is finally arrested. From the day when the spores are thrown into contact with the antherozoids they are already re-invested with a membrane.” M. Thuret remarks on this movement of rotation among the spores, that the phenomenon, however curious, does not perhaps merit much consideration. Ile does not think it necessary to the fecundation of the spores, and does not admit that the movement takes place in nature.

ITV. CERAMIACES.

Seaweeds are distinguished, by their rose or pur plish, sometimes olive or violet colour, hence called Rose-tangles. They are cellular, or rather tubular, { unsymmetrical bodies, their cells being long {, tubular, occasionally only polygonal, multiplied J by means of tetraspores and spheerospores, #* they } are in threes, as in Chondria, or fours, within s

| transparent perespore, as in Corallina officinalis,

h or mother-cell; a varicty in their fructificatlo” } which, as Dr. Lindley remarks, ‘“ seems to indicate their being the highest form of algals.” They a entirely marine species, and, according to E —

Fig. 818, Focus *2eY chiefly abound between the 35° and 48° pat Sc. allel, diminishing in number towards the equator, and being rare in the Southern hemisphere. among the genera of this order that the more gelatinous seaweeds vecur: the material out of which the swallows construct the edible nests so valued by the Chinese is supposed to be Gelidium. f lo-caria compressa and Chondrus crispus possess similar qualities:

Rhodomenia palmata, the Dulse of the Scottish coast, the Dillesk of Ireland, and the Saccharine Fucus of the Icelanders, is eagerly sought on the coasts throughout the maritime countries of Europe.

V. OHARACE.

The Charas are aquatic plants, composed of an axis consisting of parallel tubes, which are either transparent or incrusted with carbonate of lime, and of whorls of symmetrical tubular branches, multiplied by spiral-coated mucules filled with starch. They are among the most obscure creations of the vegetable world in regard to their reproductive organs, but their transparency makes them interesting objects of investigation, and they were the first in which an actual circulation of sap was observed. They inhabit stagnant fresh or sea waters, and live always immersed, giving out a foetid odour, and having a dull greenish colour. Their stems are regularly branched, brittle, and surrounded here and there by smaller branches or whorls, the axils of the uppermost whorls, concealing the reproductive organs, consisting of nucule, supposed to be analogous to the pistil, and a globule representing the anther, The order consists of three genera, Chara, Notilla, and Charopsis; the first containing on the outsides of its central tube a thick layer of calcareous matter, which is the result, according to Greville, of © peculiar economy of the plant itself, and according to Brewster, analogous to the siliceous deposit on Equisetum. Notilla, on the Contrary, is transparent, and free from all foreign matter. This Property seems to have recommended it as a subject for experiment. It appears that if the stem of any transparent Chara is examined with a good microscope, a distinct current will be seen to take place in every tube of which the plant is composed, Setting from the base of the tubes to the apex, and returning in C.vulgaris at the rate of about two lines per minute, and that . 10vement is destroyed by the application of a few drops of *Pinits; by pressure; or by lacerating the tube. M. Thuret’s account

| ssthe Structure and action of these plants is singularly interesting.

uy The antherids in all the species are in the from of orange-red oe globules, immediately below the spore-cases. These globules consist —

of eight slightly concave triangular cells, crenellate at the edge; the crenells dove-tailing together so as to form a sphere when united with a corresponding partition directed towards the centre of the cell, occupying about a third of its breadth; that part which is turned towards the antherid is clothed with a lining of red granules, the rest of the cell containing a colourless liquid which gives it transparency, and produces the appearance of the antherid being surrounded by a whitish ring. To the centre of each cell is attached an oblong vesicle filled with orange-coloured granules arranged in lines, and presenting a very remarkable circulation. The eight vesicles emanating from the eight cells converge in the centre of the antherid, where they are united by a small cellular mass; while a ninth vesicle of the same nature, but larger and bottle-shaped, fixes the antherid, its broad base being attached to a branch of the plant, while its other extremity, penetrating the four lower valves, is fixed in the central cellular mass of the antherid. From this point also are a number of wavy transparent tubes divided by partitions, in each joint of which is borne ® thread-like anthozoid rolled up on itself several times. When these tubes are young their joints contain only a small granular mass forming a nucleus of oval form and greyish colour, of irregular form and higher refractive power, as well as more defined edges at the base. This nuclei subsequently disappears, leaving a brilliant point encircled with black on each. side of the joint This is the first indication of the appearance of an anthero70l® and it is produced by the circumvolution of their thread-like body- By degrees the antherid dehisces; the valves or cells turn back on _ the branch, dragging with them the oblong central vesicle, to a extremity of which a portion of the cellular mass adheres, whe

selves, under the microscope, twisting and turning in all directions in the cavity which contains them. They eventually escape uy® sudden movement which resembles the action of a spring: o free they resemble a thread twisted up into a corkscrew form Mion three or four turns, like the fragments of spiral vessels, 1H fiel of the microscope is quickly covered with little thread-like bodies swimming with a singular tremulous motion. They beac 89 « their axis, always preserving the screw form, for their spiral a

seems to be somewhat stiff. Their motion seems to be caused by the continual agitation of two long ciliw of excessive fineness which spring from behind the anterior extremity of the spiral on which they seem to fold themselves. The posterior extremity, namely, that which is dragged along by the advancing antherozoid, is granular, thicker, and less defined than the rest of the body. When the cilice diminish in activity, it is easy to see that motion originates at their base and extends by waves in the direction of their length. Iodine, alcohol, ammonia, and the acids, stop these movements, the cilize resisting the action of ammonia longer than the other parts of the antherozoids.” The phenomena which he has described M. Thuret considers unquestionably of the same nature as in the Mosses, their function being, as he believes, impregnation; for which purpose the spore-cases seem to be constructed, being surmounted by five cells surrounding a small canal, when young forming a sort of stigmatic coronal, which disappears at a later period when the reproductive body has arrived at a certain stage of growth.

FUNGALEsS. The Fungi, or Mushrooms, form an extensive section of Thallo- Sens. Their best known form is the Mushroom, in which we recognise the true sporidia, contained in asci or sporule cases as the organs of reproduction. But it includes forms of infinite diversity, the least noticeable of which perhaps are the minute substances which appear in and upon decomposing fluids, and as vegetable parasites upon many living animals and plants. All alike, however, consist exclusively of cellular tissue, although they vag widely in their arrangement, and especially in the nature of their reproductive organs. Inthe more minute bodies just alluded to, the organ of fructification is simply an enlarged asci contain-mg the spores. But in the Mushroom the sporidia are contained 2 @ sporule case, and in some others there are movable sporal fibres or elaters. They vary widely in form, size, colour, and duration; but one of their most common characteristics is rapid Growth and brief duration. The most conspicuous species are dis- : ed by elegance of shape and bright glossy colours. But

nothing can exhibit greater extremes of development if the highest and lowest forms of Fungales are contrasted: the large fleshy Boletus, for example, which grows on the trunks of trees, composed of threads much too mould-plant,and the microscopic delicate to be distinguished by the naked eye, although the latter proves to be only a simpler form of the former. Viewed in their whole extent, the Fungales may be described as cellular flowerless plants, nourished through their thallus or mycellum; having a concentric mode of development; living in the open air; propagated by spores, colourless or brown, and sometimes enclosed in asci—that is, in transparent cells—and destitute of gonidia. ee’

The Fungales are very extensive as regards genera and species. The Rev. Mr. Berkeley gives the number as 598 genera and 4,000 species, to which new forms are being constantly added. “In are little “ Fungales Lindley, says Dr. forms,” their simplest of simple cellules placed end to composed filaments, articulated substances—the end. Such is the mould found upon various mildew of the rose-bush, and all the tribes of Mucor and Mucedo. In some of these the joints disarticulate and appear to be capable in others, spores collect in the terminal joints, of reproduction; by the rupture of the cellule that contained dispersed and are finally they are masses of cellular composition them. In a higher state of tissue of a determinate figure, the whole centre of which consists of spores attached, often four together, to the cellular tissue, which at length dries up, leaving a seed-like mass, intermixed more oF puff-balls, or sporidia contained in mem- less with flocci, as in the braneous tubes or asci, like the theca of Lichens, as in the spheris. In their most perfect state they consist of two surfaces, one * like the cortical layer of Lichen; imperforate, which is even and the other, separated into plates or cells, and called the hymenium, to whose component cells, which form a stratum resembling the pile of velvet, the spores are attached by means of little processes, and generally in fours, though occasionally the number is more OF : less.”” process of F ungales " reproductive account of the Schleiden’s highly interesting. The most simple filamentous Fung}, the thread-like cells,” he Bay? Hyphomycetes, form, “ at the end of the is de eloped; a spore on each of which protuberances,-“ narrow