. Animal physiology. Physiology, Comparative; Physiology, Comparative. REPRODUCTION BY BUDS. 549 its cavity ; and, when it is mature, it is liberated by the bursting of the walls which inclose it,— the destruction of the parent being thus necessary for the propagation of the race. Not un- frequently, a third generation may be seen within the second, previously to the setting-free of the latter; and, under the bril- liant light and high magnifying power of the solar microscope, even a fourth generation has been seen within the third. 729. Among many of the lower Articulata, the segments of the
. Animal physiology. Physiology, Comparative; Physiology, Comparative. REPRODUCTION BY BUDS. 549 its cavity ; and, when it is mature, it is liberated by the bursting of the walls which inclose it,— the destruction of the parent being thus necessary for the propagation of the race. Not un- frequently, a third generation may be seen within the second, previously to the setting-free of the latter; and, under the bril- liant light and high magnifying power of the solar microscope, even a fourth generation has been seen within the third. 729. Among many of the lower Articulata, the segments of the body appear to be capable of producing new individuals; and there are some among the Annelida, whose ordinary pro- pagation is accomplished in this manner. In some species of the Earth-worm^ the reproductive power appears to be nearly as great as in the Hydra; for a single individual having been divided into twenty-six parts, almost all of them reproduced the head and tail, and became so many new and perfect individuals; and in another experiment, the head of one of these animals was cut off eight times, and reproduced as often. In the Nais, one of the marine-worms, the last joint of the body gradually extends, and increases to the size of the rest of the animal; and a separa- tion is made by a narrowing of the preceding joint, which at last divides. Previously to its separation, however, the young one often shoots out a young one from its own last joint, in a similar. Fig. 282 Nereis Prolifera. manner; and three generations have thus been seen united. In some species of Nereis, the separation takes place nearer the middle of the body. 730. In the Planaria,—an aquatic animal, which has the same general structure with the Entozoa (particularly resembling the Fluke, common in sheep's livers), but which does not inhabit the bodies of other animals,—the power of reproducing the several. Please note that these images are extracted from scanned page images that may have been di
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