. Cassell's natural history. Animals; Animal behavior. LVUO (Nephthys proboscis, and liolding itself fixed by its setigerous feet. When swimmmg it uses the feet as oars, and moves very quickly through the water. Fresh water soon produces convulsions and death. A Worm called the Prolific Syllist belongs to the family Syllidse. It has the head distinctly seen, and the tentacles are pointed, and the creature has eyes. Dr. Johnston observed that this Syllis is more studious to divide than to unite. When it divides, the ])osterior half gi-ows a head before it is separated, so that the Worm looks li
. Cassell's natural history. Animals; Animal behavior. LVUO (Nephthys proboscis, and liolding itself fixed by its setigerous feet. When swimmmg it uses the feet as oars, and moves very quickly through the water. Fresh water soon produces convulsions and death. A Worm called the Prolific Syllist belongs to the family Syllidse. It has the head distinctly seen, and the tentacles are pointed, and the creature has eyes. Dr. Johnston observed that this Syllis is more studious to divide than to unite. When it divides, the ])osterior half gi-ows a head before it is separated, so that the Worm looks like two individuals joined together, the one holding on to the hinder extremity of the other. Quatrefages has shown that although the two halves are alike when separated, yet they have very different internal structures and gifts. The anterior half continues to eat as before, and conducts itself as an independent creature; but the other individual is devoted to the reproduction of the species, and does not eat. In anothei- allied form, the posterior half becomes self-divided into as many as six parts, each acquiring the cephalic appendages before dividing, and thus the Worm wanders about for a while, with a train of six mothers crammed with ova formed of its own tail. These separate, and die in giving birth to their ova. The family of Leaf-bearing Worms, the PhyllodocidiB, contains very beautiful Worms, which are easily distinguished from all the other Annelids. They are usually of a linear, elongated figure, and the body is furnished with a series of foliaceous lamellse on each side, -somewhat resembling elytra. They form a border, originating im- mediately above the insertions of the feet, and are in reality the cirri metamorphosed into leaf- ike appendages. These structures are supposed to be useful for respiration; but, in addition to this, they are equally useful as organs of loco- motion, for, as they follow the motions of the feet, and are capable of being partially alter
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Keywords: ., bookcentury1800, bookdecade1890, booksubjecta, booksubjectanimals
