. Zoology for high schools and colleges. Zoology. ANATOMY OF NEREIS VIRENS. 311 lands, bringing the subsoil to the surface and allowing the air to get to the roots of plants, they occasionally injure young seedling cabbage, lettuce, beets, etc., drawing them during the night into their holes, or uprooting them. The next and highest type of Annulata is the common sea-worm of our coast. Nereis virens Sars. It lives between tide-marks in holes in the mud, and can be readily obtained. The body, after the head, eyes, tentacles and bristle-bearing feet have been' carefully studied, can be opened alo
. Zoology for high schools and colleges. Zoology. ANATOMY OF NEREIS VIRENS. 311 lands, bringing the subsoil to the surface and allowing the air to get to the roots of plants, they occasionally injure young seedling cabbage, lettuce, beets, etc., drawing them during the night into their holes, or uprooting them. The next and highest type of Annulata is the common sea-worm of our coast. Nereis virens Sars. It lives between tide-marks in holes in the mud, and can be readily obtained. The body, after the head, eyes, tentacles and bristle-bearing feet have been' carefully studied, can be opened along the back by a pair of fine scissors and the dorsal and A^entral red blood-vessels Avith their connecting branches observed, as well as the alimentary canal and the nervous system. The anatomy of this worm has been described by Mr. P. M. Turnbull. It is very voracious, thrusting out its pharynx and seizing its prey with its two large pharyngeal teeth. It secretes a viscid fluid lining its hole, up which it moves, pushing itself along by its bristles and ligulae. At night, probably during the breeding season, they leave their holes, swimming on the surface of the water. The body consists of from one hundred to two hundred seg- ments. The head consists of two seg- ments, the anterior and buccal, the for- mer with four eyes and two pairs of antennse. The sec- ond segment bears four antennsB (tentacular cirri). Each of the other segments bears a pair of paddle-like appendages (rami), which may be best studied by examining one of the middle segments which. Pig. 146.—Vertical section through the integumect of an Annelid (SpfUBrodorum). c, thick cuticulai- layer with the pore-canals ; m, muscular layer ; m', muscles of the bristles, «, which retract the ceutral foot-lobe, while others pass to its dorsal glandular projection, d.—After Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloratio
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Keywords: ., bookcentury1800, bookdecade1880, bookpublishe, booksubjectzoology
