A laria esculenta, when stripped of the thin part, forms a part of the simple fare of the poorer classes of Ireland, Scotland, Iceland, Denmark, and the Faroe Islands.
The Sporochnacar are a small group, composed of the Scatter-Tuft (Sporochnus) and three other genera, which are remarkable for bearing little tufts of fine green filaments on the fronds. They are of an olive or yellowish green colour : they become flaccid on exposure to the air, acquiring a verdigris colour, and possess the property of decomposing other Alyce with which they may come in contact.
The Laminariacece, or Tangles, have a densely fibro-cellular structure, and their spores are collected together in sori on the surface of the frond. These plants are coriaceous or membranaceous in structure, and are little changed by exposure to the air. Some of them are used. Laminaria esculenta is an edible species. It grows to the length of 20 feet, and the midrib, stripped of its membranaceous covering, is the part that is eaten. L. saccharine, or the Sugar Sea-Belt, is said to be eaten by the Icelanders. In Japan it is also considered a great delicacy. L. digitate, or Sea-Wand, is eaten in Scotland, and is cried about the streets of Edinburgh as Tangle. Many of the sea-weeds belonging to this and other genera have been found to make excellent manure for grass-lands. Kelp has in many instances been used, and it has perfectly succeeded. It has been tried as a top-dressing, and singly or in combination with other manures on corn, pasture, potatoes, turnips, &c., with the best effect.
To this section belongs the Chorda filum, Sea-Whiplash, or Sea Whipcord, which is often found 30 or 40 feet in length. The frond of this plant is hollow within, interrupted at short distances, an arrange ment which appears to be for the purpose of enabling the plant to float in the water, and thus securing the same end as the more highly developed vesicles of Focus resiculosus.
The Dietyotacae, or Sea-Networks, are a larger section than the last, and are characterised by the beautifully reticulated texture of the tegu ment. Their fronds are of various forms, but all of them are ribless.
The Chordariacece and Ectocarpacece have their fronds formed of jointed filaments, which are either free or united into a compound body.
The Ectocarpacece are olivaceous or green marine plants ; their fructification is moncecious, the capsules external, and the globules placed between swollen ramuli. It oontains the genus Ectocarpus and two others.
The Rhodospermece include the following orders :—Rhodomelacere, Leurenciacece, CoratlInacece, Delesseriacex, Ithodymeniacece, Crypto nemia,cae, Cerantiacece. These orders are distinguished by their brilliant and little-fading tints, their leaf-like fronds, and the collection of their spores into sori, if scattered, by the spores being arranged on a ternary plan. The ChOndrus crispus, or Carrageen Moss, belongs to the order Cryptonemiacecc In Ireland it is used extensively as an article of food, and has lately been sold in London as a substitute for Iceland Moss. It is frequently employed, instead of isinglass, for the
manufacture of blanc-mange and jellies. It has a slight bitter flavour, which may be removed by steeping for some time previous to boiling.
Another genus of the same order is Gelidium. A species of this genus is said to be the substance collected by the swallows and used in the construction of the edible nests of Java. Strange as it may seem that a taste for birds' nests should exist among any people, yet so strong is this taste in China, that the trade in birds nests forms a very lucrative and extensive branch of commerce. Burnett, in his ' Outlines of Botany,' observes, " It has been estimated that 242,400 lbs. of birds' nests, worth in China 234,290/. and upwards, are annually exported from the Indian Archipelago." The only pre paration the birds' nests undergo is that of simple drying, without direct exposure to the sun ; after which they are packed in small boxes. They are assorted for the Chinese market into three kinds, according to their qualities; and the common price for birds' nests of the first sort at Canton is no less than 3500 dollars the pecul, or 5/. 18s. I id. per lb.; for the second, 2800 Spanish dollars the pecul ; and for the third, 1600. The collecting these birds' nests, according to Mr. Crawford, is as perilous a toil as our fearful trade of gathering samphire ; for he says, " The nests are obtained in deep and damp caves, and are most esteemed if taken before the birds have laid their eggs. The coarsest are those collected after the young have been fledged. The finest nests are the whitest ; that is, those taken before they are defiled by the young birds. They are taken twice a year, and if regularly collected, and no unusual injury offered to the caverns, the produce is very equal, and the harvest very little if at all improved by being left unmolested for a year or two. Some of the caverns are extremely difficult of access, and the nests can only be collected by persons accustomed from their youth to the office. In one place the caves are only to be approached by a perpendicular descent of many hundred feet by ladders of bamboo and rattan, over a sea rolling violently against the rocks. When the mouth of the cavern is attained, the perilous office of taking the nests must often be performed by torch-light, by penetrating into the recesses of the rock, where the slightest trip would be instantly fatal to the adventurers, who see nothing below them but the turbulent surf making its way into the chasms of the rock." (Crawford's 'Eastern Archipelago.') Several other species of Grlidium are made use of as food, more especially in the East, where they are added to dishes to render the hot and biting condiments more palatable.