. A text-book in general physiology and anatomy. Physiology, Comparative; Anatomy. 342 EESPIRATION IN LOWER ANBIALS every cell, and thus each cell can effect its exchange of gases directly, in the same manner as the single cell of the protozoan. The starfish and its allies.— In the starfish we have the simplest kind of a respiratory system. In these animals a tube is found which conveys water to various parts of. Fig. 154 Vertical section of one arm of fi stariish ; b, ampulla; d, stone canal; i, radial arabulacral vessel; ft, feet. — Davison Zoology. the body. The same tube is used in distrib
. A text-book in general physiology and anatomy. Physiology, Comparative; Anatomy. 342 EESPIRATION IN LOWER ANBIALS every cell, and thus each cell can effect its exchange of gases directly, in the same manner as the single cell of the protozoan. The starfish and its allies.— In the starfish we have the simplest kind of a respiratory system. In these animals a tube is found which conveys water to various parts of. Fig. 154 Vertical section of one arm of fi stariish ; b, ampulla; d, stone canal; i, radial arabulacral vessel; ft, feet. — Davison Zoology. the body. The same tube is used in distributing water to the tube feet (see p. 305), and this tube serves not only to make locomotion possible, but also, by the water which it carries, to distribute oxygen to various parts of the star- fish body and to receive carbon dioxide from them. These starfishes also have soft membranelike extensions of the skin that line the body cavity and project as pouches, or pockets, between the plates on the upper surface of the body. Oxygen is absorbed from the sea water into the body cavity through these thin, membranous pockets, and carbon dioxide passes out through them, also. The starfish, therefore, has two entirely distinct methods of respiration. It is to be noted that while this animal also possesses a partly developed circulatory system the oxy- gen distribution is not dependent upon it. This water- tube system of distribution is also entirely distinct from the. 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 Eddy, Walter Hollis, b. 1877. New York, Cincinnati [etc. ] American book Co
Size: 2652px × 943px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublishe, booksubjectanatomy
