Title: Cassell's natural history
Identifier: cassellsnaturalh05dunc (find matches)
Year: 1896 (1890s)
Authors: Duncan, P. Martin (Peter Martin), 1821-1891; Metcalf Collection (North Carolina State University). NCRS
Subjects: Animals; Animal behavior
Publisher: London (etc) Cassell & Company, Limited
Contributing Library: NCSU Libraries
Digitizing Sponsor: NCSU Libraries

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
NATURAL HISTORY. is brilliant in colour, with flesh and iridescent lilue tints. It is a great wanderer, burrowing often in the mud in brackish water marshes and pure sea-water shores. In its larval state, just after the tentacles are developed, it is phosphorescent, and may be seen on the shells of oysters. The White-rag Worm*, or Lurgj is common on the British shores, and varies from six to ten inches in length, being about three-tenths of an inch wide. It is of a beautiful pearly lustie, and the feet are much developed, and increase gradually in size from the head to about the middle of the body, and then decrease. It lives in the sand, burrowing into it by means of its strong
Text Appearing After Image:
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 altered from a horizontal to a perpendicular position, " they act as a bank of oars, and must be especially useful when the Worm glides from a iHviLODoeE KiMiEUGii. soHd surfacB, and finds itself unsupported in the water. Hence the species are quick and li\'ely, and swim with considerable ease." The Phyllodocidse are provided with a very large proboscis, the under side of which is roughened with rows of fleshy papillae. The one-branched feet, independent of their leaf-like appendages, are rather small, and the setae, which spring from them, and of which there is only one brush, are slender and elegant in shape. The genus Myxostomum contains little discoid parasites covered with vibratUe cilia, and they have four pairs of suckers on the sides of the belly. They have a proboscis and five pairs of * Ntphthys cicca, t SijUis jnvHfera.

Note About Images