Графични страници
PDF файл

most in winter, and at that time cover the ground with a beau. tiful green carpet, in many places which would otherwise be naked, and when little verdure is elsewhere to be seen; so at the same time they shelter and preserve the seeds, roots, germs, and embryo plants of many vegetables, which would otherwise perish. They furnish materials for birds to build their nests with, they afford a warm winter's retreat for some quadrupeds, such as bears, dormice and the like, and for numberless insects which are the food of birds and fishes, and these again the food or delight of men. Many of them grow on rocks and barren places, and by rotting away, afford the first principles of vegetation to other plants, which never else could have taken root there. Others grow in bogs and marshes, and by continual increase and decay, fill up and convert them into fertile pastures or into peat bogs, the source of inexhaustible fuel to the polar regions.

“They are applicable also to many domestic purposes. The Lycopodiums are some of them used in the dyeing of yarn, and in medicine; the Sphagnum (peat moss), and Polytrichum fur. nish convenient beds for the Laplanders, and the Hypnums are used in the tiling of houses, stopping crevices in walls, packing brittle wares, and the roots of plants for distant con. veyance.

“ To which may be added, that all in general contribute entertainment and agreeable instruction to the contemplative mind of the naturalist, at a season when few other plants offer themselves to his view.

“ The Fungi have been suspected by some to be, like spon. ges and corals, the habitations of some unknown living beings, and being alkaline, have been classed in the animal kingdom; but they are known to produce seeds, from which perfect plants have been raised; and the celebrated Hedwig, by great dex. terity of dissection, and by using microscopes of very highly magnifying powers, assures us that he has discovered both stamens and pistils, not only in this order of plants, but in the other orders of the Cryptogamous family.”*

Hepatice, or LIVERWORTS. The 3d order contains the Liverworts, which are more succulent or juicy than the mosses ; they have four valved capsules, which circumstance, and that of the capsule not opening with a lid, distinguish them from the mosses. Their name, Hepaticæ, signifies liver ; but it is not yet known whether

* Thornton's Botany.

Various uses of the mosses—Fungi-Liverworts--Derivation of the name

they received that name on account of some supposed virtue in curing diseases of the liver, or whether it was because they were thought to resemble the lobes or divisions of the liver. One of the most common genera of this order is the Junger. mannia ; you may here see (Fig. 129) a species of this, the complanata, with its parts as represented under a magnifier.

[merged small][graphic][merged small][merged small]

(a) A plant of natural size in fruit. (6) The fruit magnified, showing the sheath, the peduncle rising from it, and the capsule at top not yet burst. (c) The capsule splitting and discharging the seeds. (d) The capsule empty, showing its four valves.

Alge, or SEA WEEDS. The 4th order includes the sea weeds and frog spittle ; these have leathery fronds, with fine dust-like seed, enclosed in in. flated portions of the frond. They are almost always aquatics, generally green or reddish. One genus of this family is the Fucus (in the plural Fuci) ; these plants with some others of this order, swim on the waters of the ocean.

The FUCUS na. tans, sometimes called the gulf-weed, is very abundant in the Gulf of Florida ; and is found in various parts of the ocean, fornring masses or floating fields, many miles in extent. The plant seems to possess no distinct root, though it perhaps origin. ally vegetated on some sea-beaten shore, from whence it was by accident thrown upon the ocean's wave.

The Fucus giganteus is said to have a frond of immense length; from whence its specific name, signifying gigantic.

Sea weeds—Fuci-Gulf weed.

You are here presented (Fig. 130) with a delineation of three kinds of Fuci. (a) Fucus nodosus (knobbed fucus), this has

[merged small][graphic]

forked fronds. The knobs which appear in the fronds, aro airbladders, which render it peculiarly buoyant upon the water. This is often more than six feet long. (6) Fucus vesiculosus (bladder fucus); here the air-bladders are mostly axillary, and at the sides of the mid-rib. It varies in length from one to four feet. On account of its mucilaginous property it forms a good manure; and in some of the countries of Lapland it is boiled with meal, and given for food to cattle. (c) Fucus serratus has a beautiful, serrate or notched frond.

The Fuci, on burning, afford an impure soda called kelp.

Lichenes, or LICHENS. The 5th order contains the LICHENS ; these are various in texture, form and colour; they are leathery, woody, leaf-like, white, yellow, green and black. When wet, they often appear like green herbage ; some appear on stones or old fences and buildings; others with strong green filaments, are suspended from branches of trees and improperly called mosses. The fruit of the lichen consists of tubercles, or saucer-like bodies, in which the seeds are contained; this may be seen in the

Delineation of three kinds of Fuci-Kelp-Lichens-Of what the fruit consists.

[ocr errors]

following delineation. Fig. 131, a, represents a lichen of a

[merged small][graphic][subsumed][ocr errors]

leaf-like appearance ; here the saucer-like bodies in which the leaves are imbedded are very apparent. b, is a lichen resembling a drinking glass. c, is the rein-deer moss, furnishing almost the sole food of that useful animal, so important to the existence of the Laplander. In the middle of Europe it grows only to the height of two or three inches ; but in Lapland it sometimes attains to the height of one foot and a half.

Many of the lichens are useful on account of their colouring matter. Litmus, which is so common as a chemical test for acids and alkalies, is obtained from a species of white lichen, called Orchal or Archil, this is also used for giving a crimson colour to wool and silk ; and the powder called cudbear, used for dyeing purple, is obtained from lichen. The order Lichen has sometimes been included under one genus called lichen, and placed in the order Alge.

Fungi, or MUSHROOMS. The 6th order contains the Mushrooms, or fungus plants; these never exhibit any appearance of green herbage; they are generally corky, fleshy, or mould-like, varying much in form and colour. The fruit of some is external, of others internal. They are often of very quick growth and short duration, hence the expression which is often ironically made, “ a character of mushroom growth,” when a person has suddenly acquired consequence. The genus Agaricus, which contains the common eatable mushroom, has a convex, scaly, white head, called a pileus ; this is supported on a stalk called a stipe. On the under surface of the pileus or cup, are seen many

flesh-colour. ed membranes called gills. These gills in the young state of the mushroom, are concealed by a wrapper called a volva,

Explain Fig. 131–Uses of the lichens-Order Mushrooms.

which is considered as a kind of calyx. As the mushroom be. comes older, the volva bursts and remains upon the stipe, while the pileus, released from its confinement, extends upwards, and exhibits an uneven appearance upon its edge, caused by its Fig. 132.

separation from the volva. Fig. 132 represents the most important parts of

the mushroom ; à, b d

the gills running from the stipe to the circumference, under the pileus. b, a young mushroom, with the pileus of a

globular form, and not separated from the volva. c, the volva or wrapper, burst. ing and separating from the pileus so as to exhibit the gills beneath. d, part of the volva remaining upon the stipe in a circular form, and called annulus or ring.

“ If the mushroom be left for a time on a plate of glass, a powder will be found deposited ; this is the seed or organic germ. That these are capable of germination is evident to cultivators, who now form mushroom beds, by strewing the decayed plants on prepared beds of manure.

A species of the genus Agaricus, is common in Italy, and much valued for food; it is of a fine red and orange colour; the ancient Romans esteemed it as a great luxury. The genus Boletus contains the touchwood or spunk, which is sometimes used as tinder. The LYCOPERDON contains the puff-ball.

It is not to be expected that you will go into a minute inves. tigation of the Cryptogamous plants ; they are probably the least understood of all the visible works of nature. Philoso. phers have asserted that some of this race do not belong to the vegetable, but to the animal kingdom ; having discovered in. sects in mushrooms, they say that like the sponge and the corals, these should be classed among animal productions. Few, however, at present, entertain this belief; and the fact of their having been raised from seed sprinkled on the earth, proves them to be of vegetable growth. A curious field of inquiry presents itself in the consideration of the difference between animal and vegetable life. This we shall hereafter partially

[ocr errors]


Explain Fig. 132—Mushrooms capable of germination-Different genera Opinions of some philosophers respecting the Cryptogamous plants.

« ПредишнаНапред »