. Elements of zoölogy. Zoology. IOO CRABS AND INSECTS. sects, into a second stomach, or gizzard, d, that is provided with muscular walls and chitinous plates. From here it passes to the true stomach/, and finally to the intestine h. Circulation.—The heart, If, is tubular in shape, ex- tending along the back, and composed of numerous sacs, separated by valves that allow the blood to flow toward the head, where it branches out, re- turning through the tissues, there being no true veins or Fig. 113.—S, spiracle or breathing-plate, with the slit in the center which opens to take in air.
. Elements of zoölogy. Zoology. IOO CRABS AND INSECTS. sects, into a second stomach, or gizzard, d, that is provided with muscular walls and chitinous plates. From here it passes to the true stomach/, and finally to the intestine h. Circulation.—The heart, If, is tubular in shape, ex- tending along the back, and composed of numerous sacs, separated by valves that allow the blood to flow toward the head, where it branches out, re- turning through the tissues, there being no true veins or Fig. 113.—S, spiracle or breathing-plate, with the slit in the center which opens to take in air. T, part of a breathing-tube, showing the spiral thread which keeps it in its round 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
