. Animal studies. 48 ANIMAL STUDIES process bearing on its end an opening which becomes the mouth (Fig. 21, A). Around the margin of the bell nu- merous tentacles develop, and at the same time the gelati- nous substance situated between the outer and inner layers of the bell expands to a relatively enormous degree, giving it an increasing globular form and glassy Fig. 21.—A jelly-fish (Gonionemus), slightly enlarged. The stalked mouth is shown in dotted outline. B, C, enlarged portions of a hydroid colony bearing the mouth and tentacles; j, a capsule within which the jelly-fish de
. Animal studies. 48 ANIMAL STUDIES process bearing on its end an opening which becomes the mouth (Fig. 21, A). Around the margin of the bell nu- merous tentacles develop, and at the same time the gelati- nous substance situated between the outer and inner layers of the bell expands to a relatively enormous degree, giving it an increasing globular form and glassy Fig. 21.—A jelly-fish (Gonionemus), slightly enlarged. The stalked mouth is shown in dotted outline. B, C, enlarged portions of a hydroid colony bearing the mouth and tentacles; j, a capsule within which the jelly-fish develop ; D, dia- gram of jelly-fish, illustrating its method of locomotion. Finally, vigorous movements rupture the connection with the parent, and this newly developed outgrowth, usually small, becomes an independent organism popularly termed a jelly-fish. While the external form of the jelly-fish appears to be widely different from the hydranths, a more careful study shows the difference to be superficial. Some zoolo- gists believe that jelly-fishes are simply buds which have become fitted to separate and swim away from the colony in order to distribute the young, as described hereafter. When the stalked colonies are very abundant the jelly-. 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 Jordan, David Starr, 1851-1931; Kellogg, Vernon L. [from old catalog].
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Keywords: ., bookauthorjordanda, bookcentury1900, bookdecade1900, bookyear1903
