. Ocean wonders: a companion for the seaside. d at our verydoors. Until lately this might be truly affirmed of the com-mon five-fingered jack, as seamen call the star-fish. Onereason for our ignorance of this class of marine animals isfound in the fact that, previous to the general introductionof aquaria, naturalists could rarely get anything but theskeletons of these creatures to examine—a very inadequatemeans of learning the habits of the living animal. If we understand the principle upon which the five-rayedstar-fish is constructed, we shall readily perceive that all theother varieties are
. Ocean wonders: a companion for the seaside. d at our verydoors. Until lately this might be truly affirmed of the com-mon five-fingered jack, as seamen call the star-fish. Onereason for our ignorance of this class of marine animals isfound in the fact that, previous to the general introductionof aquaria, naturalists could rarely get anything but theskeletons of these creatures to examine—a very inadequatemeans of learning the habits of the living animal. If we understand the principle upon which the five-rayedstar-fish is constructed, we shall readily perceive that all theother varieties are simply modifications of this. The firstthing to be learned about this animal is that it has two dis-tinct sides—an upper, slightly convex, and an under or oral 1 See Contributions to the Natural History of the United States, by Loui3Agassiz, vol. iv STAR-FISHES. 135 side. The upper is rough and tuberculous; the under issoft, and contains all the vital and locomotory organs. It isdivided by five furrows, all leading to the mouth, which of. Star-Fisu, showing Process of reproducing- its Four Lost Arms. course connects with the digestive cavity; in this it some-what resembles the actiniae, but it differs wholly from themin the relative powers of expansion and contraction, as wellas locomotion. The rays of the star-fish are usually on the same plane,but the animal has the power of raising them so as to pro-gress over obstructions which may be in its way. It can walkon a level or ascend elevations with apparently the same it is not the rays themselves which perform the work oflocomotion. Its organs of motion we shall presently de-scribe ; but, in the first place, let us see how this star-fish 136 THE OCEAN. looks when first taken from the water. Almost immediatelythe soft nnder parts seem to shrink away, and nothing sub-stantial remains bnt the upper surface; this is perforatedwith pores, through which the water enters to all parts ofthe body by specific channels; it is
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