while it yields spores, contained in receptacles perfectly

CORALLINA OFFICINALIS.

analogous to those of the algæ of the red series, to which its colour also allies it. These spores were observed and figured by Ellis; and it is therefore the more strange that the vegetable nature of the family has not been earlier acknowledged. Corallina officinalis generally occurs in society, covering the bottoms of shallow tide

pools with its jointed fronds, which afford a welcome resting-place to many of the smaller algae and to marine animals. It always springs from a broad, calcareous base, often of considerable thickness, which incrusts the surface of the rock. It commences to vegetate, though feebly, immediately within the limit of highwater, and extends throughout the whole littoral zone, gradually acquiring fuller development as the water deepens; and the best specimens are always to be found nearest to low-water mark. It is occasionally dredged from the depth of three or four fathoms, or perhaps more; but specimens from water of that depth are less perfect than those collected about low-water mark, clearly shewing that, at that level, the species is in the situation best adapted to its nature. The species of the genus Corallina are very imperfectly known, and many supposed species may ultimately prove to be merely varieties of this common and very generally diffused

plant, which, in some form or other, inhabits the shores of most temperate latitudes.

Along with Corallina officinalis, and also creeping among the roots of various other algæ, may often be seen the fronds of a lichenoid species of calcareous plant, Melobesia (or Nullipora) lichenoides, affixed to the surface of the rocky soil. This is of the same family as the Corallina, but simpler in structure. By some authors it is supposed to be merely the imperfectly developed state of a coralline; but the evidence for this opinion does not appear satisfactory, and in the imperfect state of our knowledge it is better to consider these plants distinct. In appearance they are widely different, though similar in microscopic structure and substance. The Melobesia belongs to a group of the family, characteristic of a deeper water, and which we shall have occasion to speak of in our chapter on Dredging.

The very imperfect outline which I have just given of the several groups of marine plants, is all that the plan of this little volume admits of, without trenching too much on subjects of perhaps more general interest. The great elegance of many of the sea-weeds, and the ease with which specimens may be preserved, retaining much of their original beauty, attract many persons who occasionally visit the sea-shore; and sea-weeds are collected either as objects of scientific interest, or for the manufacture of pictures for albums or screens. Those who collect sea-weeds for the latter purposes, in general care little to know their history; but perhaps when some of its facts are known, they may be regarded as not without interest. I have, therefore, mentioned some

of the principles on which the classification of these plants is based, and described some of the commoner species of our shores. For a more detailed history of the family, I must refer my readers to books more expressly written on the subject.*

* See the Author's "Phycologia Britannica," containing coloured plates and detailed descriptions of all the British Sea-weeds: also, his "Manual of the British Marine Algæ," 2nd edit., with 27 plates of genera (in preparation).

Were we

In the vegetation of the sea, nature has provided both shelter and food for an infinitude of animals. to speak of the uses of sea-weeds, and confine ourselves to their adaptation to the wants of man, we should much misinterpret the office which this portion of the vegetable world discharges in the general economy. However great their uses to man, these are absolutely insignificant in comparison to those benefits for which the lower tribes of animated nature are indebted to the sea-weeds. Troop after troop of animals, one more highly organized than another, either derives its nourishment from the sea-weed itself, or uses the submarine forest as a hunting-ground, where it fulfils the ap

80

VARIETY OF ANIMALS.

pointed course of its busy life. Adhering to the roots of sea-weeds we find the scarcely organized, but obviously animated sponge, whose place in the scale of creation seems so nearly balanced between the animal and the vegetable that naturalists have debated to which of the kingdoms it properly belongs. To the stems and leaves adhere multitudes of incrusting animals, some of which, till we examine them somewhat closely, and watch their animal motions and propensities with some care, seem to consist merely of masses of jelly; while others display, in their outward forms, the branching appearance of mosses, every branch clothed with scales, and crowned, when the animal is in vigour, with starry flowers. The rocks from which the sea-weeds spring afford a resting-place to stationary animals, which, in the shelter of these submerged groves, watch the approach of prey; and through the branches, in every direction, tribes as different from each other in form and structure as it is possible to conceive, sport and multiply, and contend in ceaseless motion. spot of rock is absolutely desert, and no sea-weed grows that does not support its multitude of living things. The zoologist, therefore, on any rocky shore, may find abundant occupation; and he who does not limit himself to the mere collection and determination of new species, but enters into the more noble departments of his science, anatomy and physiology, - will in the most barren places find animals, the investigation of whose history will afford him constant sources of plea

sure.

No

At the base of the animal scale, and apparently in