. First lessons in zoology. Zoology. 126 FIRST LESSONS IN ZOOLOGY ma}' be over a meter (39 in.) in height. In color they may be red, purple, orantje, gray, and sometimes blue. Examine a batli sponge and note the holes in it. These are to let in and out the sea-water, in which float the minute bits of animal or plant substance on which the sponge feeds. This water also brings for the breathing of the sponge, and carries away the carbon dioxide given off by it. But the sponge has no special organs, its soft flesh being able to digest food and take up oxygen without stom- ach or lungs. Th
. First lessons in zoology. Zoology. 126 FIRST LESSONS IN ZOOLOGY ma}' be over a meter (39 in.) in height. In color they may be red, purple, orantje, gray, and sometimes blue. Examine a batli sponge and note the holes in it. These are to let in and out the sea-water, in which float the minute bits of animal or plant substance on which the sponge feeds. This water also brings for the breathing of the sponge, and carries away the carbon dioxide given off by it. But the sponge has no special organs, its soft flesh being able to digest food and take up oxygen without stom- ach or lungs. The living sponges are col- lected by divers, or are dragged up b)- men in boats with long- poled hooks or dredges. They are first killed by ex- posure to the air, and then thrown into tanks of water. Here the flesh decays away, leaving the tough, horn)', or ,, â ,,,, , , ^ leathery skeleton, which, I-k;. 87.â 1 lit- bkeletnri of a â ' " glass " sponge (skeleton com- when cleaned, bleached, and loosed of siliccrms spicules) from . -.â i â j r i i. J:,pan. (Natural size; fmm trimmed, IS ready for market. ) Some sponges have a lime and some a glass skeleton instead of a horny one, and the glass slv'elctons are often very beautiful (see fig. '$>'/). All the sponges compose the animal branch called Poi-ifcra. Sea-anemones and corals.âThe sea-anemones which are common in tide-pools, ami the coral animals ^\'hich live in tropic and sub-tropic oceans, ha\'e the same type. 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 Kellogg, Vernon L. (Vernon Lyman), 1867-1937. New York, H. Holt and Company
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1903
