. A manual of elementary zoology . Zoology. ANNELIDA .- THE EARTHWORM, NEREIS ±1$ and lying end to end. The cilia set up a current which sweeps in and carries off the excretory granules formed by the yellow cells, together with substances taken from the blood and excreted by the walls of the tubes. Some of these, in the form of granules, colour the brown part of the tube. Earthworms have no special respiratory organs, but an inter-. FlG. 142.—A diagram of a nephridium of the earthworm. Brown, ciliated tube; , muscular tube; , glandular, non-ciliated tube; , narrow tube, ci
. A manual of elementary zoology . Zoology. ANNELIDA .- THE EARTHWORM, NEREIS ±1$ and lying end to end. The cilia set up a current which sweeps in and carries off the excretory granules formed by the yellow cells, together with substances taken from the blood and excreted by the walls of the tubes. Some of these, in the form of granules, colour the brown part of the tube. Earthworms have no special respiratory organs, but an inter-. FlG. 142.—A diagram of a nephridium of the earthworm. Brown, ciliated tube; , muscular tube; , glandular, non-ciliated tube; , narrow tube, ciliated in parts; nst., nephrostome; Sep., septum; , connective tissue with vesicular cells and blood vessels; i, 2, 3, the three banks of the tube. For details of structure see Plate XVII. change of gases with the air takes place in the skin, which is richly supplied with blood vessels. The blood of an earthworm is red on account of the presence of haemoglobin, which is in solution, not in corpuscles. Colourless corpuscles are present. The blood-vascular system is very complicated. Its main outlines are as follows. A large dorsal vessel runs the whole length of the body from the hinder Blood Vessel!.. 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 Borradaile, L. A. (Lancelot Alexander), 1872-1945. London : H. Frowde, Hodder & Stoughton
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectzoology, bookyear1920
