. Elements of zoölogy. Zoology. CHAPTER III. THIRD BRANCH OF ANIMALS. HYDROIDS, Etc. {Ccelenterata, hollow intestine). General Characteristics.—A simple sac, as the Hydra, composed of two-cell layers, possessing a stomach, or di- gestive cavity. The mouth is encircled by tentacles, which are hollow, and connect with the stomach. Class I.—Hydrozoa. Order I. Hydroids.—One of the commonest animals of the aquarium, if the water is taken from the brook or stream, is the Hydra (Fig. 13)—a simple, elongated stomach one quarter of an inch in length, end- ing in a mouth that is surrounded by from five
. Elements of zoölogy. Zoology. CHAPTER III. THIRD BRANCH OF ANIMALS. HYDROIDS, Etc. {Ccelenterata, hollow intestine). General Characteristics.—A simple sac, as the Hydra, composed of two-cell layers, possessing a stomach, or di- gestive cavity. The mouth is encircled by tentacles, which are hollow, and connect with the stomach. Class I.—Hydrozoa. Order I. Hydroids.—One of the commonest animals of the aquarium, if the water is taken from the brook or stream, is the Hydra (Fig. 13)—a simple, elongated stomach one quarter of an inch in length, end- ing in a mouth that is surrounded by from five to eight tentacles that are extensions of the body, hollow, and connecting with it. If examined closely, myriads of small cells will be seen, many of which contain deli- cate threads or darts, called lassoes, that are thrown out as weapons of defense (Fig. 14). By cutting a Hydra. Fig. 13.—Fresh-water Hydra viridis. 1. Long-armed Hydra feeding on small ani- mals, a. 2. Hydra fusca throwing off young 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 Holder, Charles Frederick, 1851-1915; Holder, Joseph Bassett, 1824-1888, joint author. New York : D. Appleton and company
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1884
