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     It may have occupied you, gentle reader, the whole morning, in collecting the treasures to which we are about to devote half an hour's gossip. To be successful in collecting sea-weeds, you ought to follow the retreating tide step by step. When it has reached its farthest, then you may expect to be rewarded, especially if the sea bottom be rocky and uneven. There is nothing like broken ground for studying the marine flora. As you have walked along you have been surprised at the marvellous abundance of sea-weeds of every size and colour, occupying nearly every available patch of the area.
     A rich meadow in June does not bring forth a more charming variety of grasses and flowers than does the rocky ground between high and low tides. Your vasculum speedily gets filled, to say nothing of the monsters as tall as yourself, which the most enthusiastic botanist would never dream of "mounting." All that you can do with them is to examine them, to cut off such portions as are interesting, say the fructifying organs; or examine them carefully for the rich store of zoophytes, parasitic sea-weeds, &c., usually attached to them. Supposing you to have exhausted a collecting ground like this, you may add still further to your list by taking a boat, and dragging the bottom with a clawed drag. Much the same difference occurs with the marine flora as the terrestrial. Height above the sea-level materially influences the distribution of the genera and species on land, and depth does the same with sea-weeds below it. Those who wish to study the general laws which regulate this apportionment of animal and vegetable life, are referred to Professor Edward Forbes's theory of the zones of depth which belt every island and mainland.
     Sea-weeds are roughly, but sharply, divided into three distinct groups, according to the colour of their spores, which are black (or olive), red, and green. The names given to these are Melanosperms, Rhodosperms, and Chlorosperms. Minor, but important subdivisions again occur, based upon the peculiar character of the spores themselves. We will take the black or olive group of sea-weeds first, as they are most abundant, as well as strongest and largest. Indeed, these latter qualities enable them completely to monopolise the ground in many instances, to the complete exclusion of diminutive species, which are forced in self defence often to become parasitic on their more powerful neighbours. In this respect, therefore, their smallness may actually be advantageous to them. We have spoken of such species as parasitic, but this must not be understood in the sense in which we understand parasitism in terrestrial plants. Properly speaking, sea-weeds have no real roots, nor do they need any, as they do not draw their nutriment from the earth, but from the sea water. The smaller sea-weeds have no appearance of roots at all, and, in the larger, you will readily see that the fibrils of the stem, which look like roots, are in reality only a kind of clasper, to get firm hold of the rocks by. Their usual mode of anchoring or attaching themselves is by a sort of disk. This is seen more especially in the chorda filum, or "sea-cord," an object you cannot fail to have recognised in the dark olive, almost black, round, cord-like weed, perhaps many feet in length, which lay entwined among other sea-weeds. This particular weed often reaches the length of twenty to forty feet.
     By far the commonest of these "black" spored sea-weeds is that group popularly known as "sea-wracks," which you may see lying in dark, unattractive heaps at low water. First, there is the "black tang," or "bladder-wrack" (Fucus vesiculosus) whose long fronds are often two feet in length. These fork repeatedly into what we may call branches, each having a stout mid-rib running down the centre, and covered with warty tubercles, or bladders, arranged in pairs (Fig. 7). The presence of this mid-rib distinguishes the species vesiculosus from the nearly allied species nodosus, in which the mid-rib is altogether absent. The "bladders," to which we have referred, are hollow, and filled with air, so as to render the weed buoyant in the water. It is a common practical joke with sea-side boatmen, to persuade youngsters to place such bladdered sea-weeds on the fire, telling them some tale or another to encourage them to do so; but well aware of the volleys of explosions that will occur if their advice be carried out. The tips of the fronds or "branches" of these "wracks" will sometimes appear swollen, and covered with little tubercles scarcely raised above the surface. These contain the arrangement for the fructification of the plant, which is exceedingly curious, and well worth a little further consideration. Each of the little frustrules has a minute opening, through which their contents escape.

     If we cut one of these tips or tubercles across, then each frustrule will be seen representing a cell or internal cavity, enclosing, in one plant, what are called antheridia, and, in another, the spores (see Fig. 8, a). The former are usually regarded as the male, and the latter as the female organs. In every case, both are produced on separate plants. The antheridia are little bags containing small bodies called zoospores (b). These no sooner escape in the way mentioned, than they move about in the water as if they were little animals, and not plants at all. The spores are little grains of an oblong shape, which ultimately separate into a certain number of parts (c). These perform the functions of seeds, which are fertilised by the zoospores, just as the ovules are by the pollen of flowering plants.

     The serrated wrack (Fucus serratus) resembles the vesiculosus in its general form, but it may at once be distinguished by its having no air-bladders, and by the edges of the fronds being serrated. Like the former, its fruit is borne at the tips of the fronds. Indeed, this species is usually recommended as the best for microscopical examination of the phenomena we have been describing. Professor Harvey advises that fresh specimens should be collected in winter or early spring, and, being removed from the water, that they should be left till they were partially dry. As the surface dries there will exude from the pores of the receptacle drops of a thick orange-coloured fluid, which, on being placed under a microscope and moistened with salt water, will be seen to be composed of innumerable cellules, from which will issue troops of these atoms. No sooner are they liberated, than they commence those singular zoosporic motions which naturalists have found so difficult to reconcile with vegetable life. The species of "sea-wrack" however, that is best known, especially for the explosive power of its bladders when treated in the manner aforesaid, is the "knotted wrack" (Fucus nodosus, Fig. 9).

     In this species the receptacles which form the fructification are not terminal, as in that just mentioned, but are borne in stalks or pedicels issuing from either side of the fronds. In the "knotted wrack," also, the spore separates into four, whence their name of tetraspores (Fig. 9 a). In the "serrated wrack," however, these spores divide into eight parts, called sporules. Another kind of wrack, nearly as well known as the above, is the Fucus canaliculatus, having fronds only a few inches in length, and the spores separated into two spores (see Fig. 10 a). Besides the above, there are two or three other species of Fucus, of a less common occurrence. The word "wrack," it may be observed, is derived from the French varec, which signifies a sea-weed.

     After a storm, you will scarcely fail to see strewn on the beach, just above high-water mark, a sea-weed with a long thick stem of three or four feet, and having its leaves or fronds digitate, or separating from a common base, just like the fingers of the human hand. This is the Laminaria digitata. An allied and almost equally common species, distinguished by the greater length of its fronds, is L. saccharina. After this weed has been lying in the sun for a few hours, it becomes more or less covered with a hoar-frost-like substance, which is sweet, and resembles the "mannite" sold in chemists' shops, hence the name of the species. The stems of the two latter are tough, and become hard when dried, so that it is not uncommon to see portions turned into fork handles, the prong of the fork being inserted when the portion was soft, and recently cut off.
     On various parts of the rocks, during your rambles, you may have observed a little, bushy-tufted, olive-coloured sea-weed, called Halidrys siliquosa (Fig. 11). It takes its name from two Greek words signifying "oak-tree." It possesses bladders, or air-vessels, which in shape resemble pods, hence its specific name of siliquosa. This species is very common on the Welsh coasts, and everywhere it is a favourite with the naturalist, on account of the numerous small zoophytes, &c., it harbours among its dense fronds.

     The Rhodosperms comprehend the most beautiful of all species of sea-weeds, and hence they are most sought after by collectors, and for ornamental purposes. Their tints of scarlet and red are of various shades, and the group includes species whose fronds are not red at all. Nearly every species grows submerged, and a large number of them in deep water. The latter, therefore, can only be obtained by dredging, or after a storm has uprooted them and cast them ashore. Even then, unless you be fortunate enough to gather them soon after they have been cast up, they will be almost worthless for herbarium purposes, on account of their being soon acted upon by the sun, so as to lose their bright colours. On the stems of Laminaria, above-mentioned, we may find the peculiar dark-red Polysiphonia urceolata, whose jar-shaped fruits are very pretty objects when seen through a low magnifying power. The Chlylocladia articulate, also, is a good specimen to mount, because of the readiness with which it adheres. This can easily be identified by the jointed branches, whence its specific name. Unfortunately, however, it soon fades, even in the herbarium, but it remains a pretty object nevertheless. In the little rock-pools you will notice the sides frequently covered with a red, limy incrustation. This is the base of the coralline sea-weed

     (Corallina officinalis, Fig. 12), a little plant of great interest, and long believed to belong to the animal kingdom, on account of the quantity of carbonate of lime it secretes. It soon bleaches, and then assumes a tint of dirty whiteness. Other algae are now known which have the same power of secreting lime, among which are the genera Jania, Acetabularia, Liagora, and Melobesia. Perhaps one of the most beautiful of the Rhodosperms is the Delesseria sanguinea, whose specific name greatly assists in its identification. Its colour is of the most beautiful scarlet, and you may further learn to distinguish it by its mid-rib and distinct nervures. Few objects look better in the herbarium, as it dries well without losing its colour, and its mucus acts as a natural gum and causes it to adhere firmly. The Ptilota plumose is another beautiful red sea-weed, whose feather-like fronds will assist you in identifying it. The stiffer, bristle-like fronds of Griffithsia setacea are worth notice, and you will hardly fail to find it growing in the darker crannies of the rock-pools. When a newly-gathered specimen is placed in fresh water, the membrane bursts, and the red colouring-matter is shot out.

     A common, but not obscure sea-weed, is the "Dulse," Eliodymenia palmate (Fig. 13), so called from its palmate form. This is an edible weed, and capable of being cooked. The fronds of the Porphyra laciniata much resemble the common green laver, except that they are of a bright scarlet. They are so thin that they cling to your fingers like a film when you attempt to lift them out of the water, and they give the young beginner infinite trouble in his endeavours to arrange them in his herbarium. Abundant in almost every rock-pool you will find the Plocamium coccineum (Fig. 14), a weed with a beautiful crimson hue, which, as usual, soon fades, and ultimately subsides into a dirty white.

     Occasionally you may stumble across a rarity or two, such as the "Peacock," or "Turkey-feather" laver (Padina pavonia), growing where it can enjoy the full light and heat of the sun. This is one of the most charming of all our sea-weeds, and from its varying tints well deserves the name of "Peacock." Nitopliyllum punctatum is also a handsome plant, which can easily be distinguished from the Delesseria, to which it bears some resemblance, by the absence of a mid-rib. Its colour is of a delicate crimson hue. The "Carrageen," or "Irish" moss (Chondrus crispus, Fig. 15), is well known from its supposed medicinal powers. Although it is included among the Rhodosperms, it is often of a pale greenish colour. It grows in large masses, and is one of our commonest weeds. When washed and boiled down into a jelly, flavoured with lemon, it is said to be very pleasant.

     The black or olive-coloured sea-weeds may be distinguished for their size, and the red for their beauty, but there can be no doubt that the green (Chlorosperms) are by far the most abundant. You can hardly stir at low water without noticing meadows of a fine, thread-like sea-weed mantling every stone and piece of rock with its dark, almost sap-green. This is the Enteromorpha compressa, a plant capable of great variation in the shape and size of its fronds. All the true green sea-weeds are notorious for their power of secreting oxygen, and this peculiarity must be of great value to the marine animals, which find at once a protection and invigoration amid their dense fronds. This oxygen-forming power is especially noticeable in the common green laver (Ulva latissima), hence its value in the marine aquarium. Very abundant almost everywhere the young collector will find Cladophora rupestris and C. arcta; the former a coarse, horse-hair sort of sea-weed, and the latter a trifle prettier. But by far the most graceful and elegant of the Melanosperms is the pretty little Bryopsis plumose, not a common plant, and one which, once seen, will be always remembered afterwards. Its specific name of "feathery" is a capital description of its general appearance.
     "How to mount sea-weeds," so as to make them present something of their original beauty as seen when their delicate fronds were waving in the water, is a very important and sometimes difficult problem to the young collector. The best method is first to separate the specimens, and then to lay each on the edge of a plate in which there is water. They should not be placed in the water, however, but just on the side, so that they may imbibe sufficient moisture during the next operation without being actually immersed. Then take a piece of stiff drawing-paper and push it under the water slowly and carefully, so as to prevent air-bubbles forming on the surface, otherwise the subsequent treatment will cause the paper to be raised into folds and wrinkles. Having prepared the paper to receive your sea-weeds, next draw the latter gently over it, with the root-end towards yourself. Then, by means of a smooth, blunt needle, you will be able to keep the stem and fronds from being entangled. Here you will be obliged to use your own experience and judgement as to their natural position, and the angle at which they ramified from each other when living. The large branches should be laid out in this manner first, after which proceed to arrange the minor ones. If this process be done deliberately and without precipitation, the tiniest and smallest of the branches and filaments may be arranged in their proper places. No fingers are so well fitted for this delicate operation as those of a lady, and we have never yet seen sea-weeds whose arrangement for skill and taste could compare with those of the gentler sex. But when carefully mounted and properly named, few objects look better, or are fitter for presents. To look over an album of well and neatly-arranged sea-weeds is a genuine treat, and even the most indifferent admirer of nature will here be forced to pay his tribute of admiration. There is something great as well as pretty in the presence of these "flowers of the sea." Just as the land vegetation exhales the gas absolutely necessary to terrestrial animals, and, at the same time, furnishes them with food, so do these sea-weeds secrete that oxygen without which the swarming myriads of marine life would die of asphyxiation; taking up, meantime, the carbonic acid, absorbing it into their tissues, and thus turning it into the solid, nutritious, and in many cases the only food obtainable by them.