But let us pass by these subtle speculations to turn to a class of animals in the case of which we may speak with more propriety than in the case of polyps and other zoöphytes of a plural soul, since physically and psychically they act in every respect as if they had grown together out of five or more individuals,—I mean the Echinoderms in general and the Star-fish (_Asteroidea_) in particular. In the following paragraphs, for the sake of brevity, I shall speak of only five-rayed star-fishes, because the sacred number five is the one that lies at the basis of the physical structure of the great majority of star-fishes developed from the egg, and of all other echinoderms, although there really do occur star-fishes which are supplied, some with more and some with less than five rays,—single rays often being cast off and a larger number growing out in their places,—and although many species are regularly and normally supplied with more than five rays. From visits to the sea-shore or to aquariums, at any rate from pictures, my readers all know how a star-fish in general looks. In the first cut which accompanies this article a number of echinoderms are presented. The star-fish is in the centre to the left. It resembles the decorative star of an Order, and has short or long, broad or slender rays, as the case may be, and a disc-shaped central body. The observation which is most important for our present discussion, and which strikes us on first seeing a star-fish, or its relatives the sea-urchin and the sea-anemone, consists of the fact that these animals possess no head, which even the most insignificant worm or insect does not lack, and that consequently its organs are in want of a guiding, regulative member, possessing externally organs of sense and having within a brain with the power to communicate the requisite commands for the movement and the conduct of the same. On the contrary, each single branch or ray possesses its own individual nervous system; and in the case of the voluntary separation of the rays, which frequently occurs, is able to continue life of its own independent accord, developing itself by the growth of new rays into a new and complete star-fish. (See Fig. 2.) But these five or more nervous systems do not radiate from a common central nerve-ganglion which might be termed a central brain, but are merely joined to a nerve-ring which lies in a common central portion, encircling the esophagus; this nerve-ring in the majority of cases forms a regular polygonic figure, and into each angle of the polygon the nerve-cord of a ray enters. It will be seen from this structural arrangement of things, that the psychical and mental guidance of these animals is entrusted to a board of five members who possess, it is true, sentient communication with each other, but act without the intermediation of a presiding officer. [Illustration: Fig. 2.—COMET-FORM OF ARM OF A STAR-FISH. A cast-off arm re-forming by the sprouting of four new rays.]