. Zoology : for students and general readers . Zoology. DEVELOPMENT OF JELLT-FISHES. 6? shorter and thicker than in the males. The eggs pass out of the mouth into the water along the channeled arms, and in October the ciliated gastrula becomes pear-shaped and attaches itself to rocks, dead shells, or sea-weeds, and then assumes a Hydra form with often twenty-four very long tentacles. This stage was originally described as a distinct animal under the name of Scyphistoma. In this Scyphis- toma stage (Fig. 45) it remains about edghteen months. Toward the end of this period the body increases in s
. Zoology : for students and general readers . Zoology. DEVELOPMENT OF JELLT-FISHES. 6? shorter and thicker than in the males. The eggs pass out of the mouth into the water along the channeled arms, and in October the ciliated gastrula becomes pear-shaped and attaches itself to rocks, dead shells, or sea-weeds, and then assumes a Hydra form with often twenty-four very long tentacles. This stage was originally described as a distinct animal under the name of Scyphistoma. In this Scyphis- toma stage (Fig. 45) it remains about edghteen months. Toward the end of this period the body increases in size and divides into a series of cup-shaped disks. These saucer- like disks are scalloped on the upturned edge, tentacles bud. Fig 48 —iiureha flaiidiila —After Agassis out, and the animal assumes the Strobila stage (Fig. 46). Finally, the disks separate, the upper one becomes detached and dies, but the others swim away in the Ephyra form (Fig. 47), when about a fifth of an inch in diameter, and toward the middle or end of summer becomes an adult Aurelia (Fig. 48). Though the Aurelia has lasso-cells it is not poisonous to bathers. Not so, however, witli the gigantic Cyanea arctica, whose long tentacles are poisonous ; fishermen as well as bathers being often annoyed by them. This giant jelly-fish sometimes attains a diameter of from three to five feet across. 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: 1599px × 1563px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1879
