. Zoology : for students and general readers . Zoology. Fig. 179.—The Ship-worm, t, siphons; p, pallets ; c, collar ; s, shell; /, foot. and a half old the germ appears as in Fig. 178, B, the shell almost coTering the larva. Soon after this the velum becomes larger, and then decreases, the gills arise, the audi- tory sacs develop, the foot grows, though not reaching to the edge of the shell, and the larva can. still swim about free in the water. When of the size of a grain of millet, it becomes spherical, as in Fig. 180, C, brown and opaque. The long and slender foot projects far out of the sh
. Zoology : for students and general readers . Zoology. Fig. 179.—The Ship-worm, t, siphons; p, pallets ; c, collar ; s, shell; /, foot. and a half old the germ appears as in Fig. 178, B, the shell almost coTering the larva. Soon after this the velum becomes larger, and then decreases, the gills arise, the audi- tory sacs develop, the foot grows, though not reaching to the edge of the shell, and the larva can. still swim about free in the water. When of the size of a grain of millet, it becomes spherical, as in Fig. 180, C, brown and opaque. The long and slender foot projects far out of the shell, and the velum assumes the form of a swollen ring on which is a double crown of cilia. The ears and pig. IsO.—Development of the Ship-worm. -1 1 _ ,„ „„.-l A, egg, with the yolk once divided; B, the eyes develop moie, ana veUger enclosed by the Wvalve shells ; C, ad- the animal alternately S^itlel'-QuaSeU's.'"'''°°'^^'"'™''" swims with its velum, or walks by means of the foot. At this stage Quatre- fages thinks it seeks the piles of wharves and floating wood, into which it bores and comf)letes its metamor- phosis. On the coast of New England the ship-worm lays eggs in May and probably through the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Packard, A. S. (Alpheus Spring), 1839-1905. New York : Henry Holt
Size: 1761px × 1419px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1879
