. Principles of modern biology. Biology. 294 - Multicellular Animals, Especially Man EXCRETORY PORE EXCRETORY VESSEL GASTROVASCULAR CAVITY PHARYNX MOUTH. Fig. 16-5. Planaria, a common flatworm. Diagram of a specimen with digestive system injected with India ink. Note that the ink flows into all branches of the gastrovascular cavity. side of the head there is a small blunt-pointed lateral projection, the auricle, which is thought to be a receptor of tactile stimuli. The mouth of Planaria is found at the tip of a hoselike muscular organ, the pharynx (Fig. 16-7). The pharynx protrudes out from th
. Principles of modern biology. Biology. 294 - Multicellular Animals, Especially Man EXCRETORY PORE EXCRETORY VESSEL GASTROVASCULAR CAVITY PHARYNX MOUTH. Fig. 16-5. Planaria, a common flatworm. Diagram of a specimen with digestive system injected with India ink. Note that the ink flows into all branches of the gastrovascular cavity. side of the head there is a small blunt-pointed lateral projection, the auricle, which is thought to be a receptor of tactile stimuli. The mouth of Planaria is found at the tip of a hoselike muscular organ, the pharynx (Fig. 16-7). The pharynx protrudes out from the ventral surface only when the planarian is feeding; and at all other times it is with- drawn into the pharyngeal pouch (Fig. 16-7). Planaria feeds upon minute organisms and particles of organic matter on the bottom of the pond. The food passes through the mouth and pharynx into the branches of the gastro- vascular cavity. The full extent of this branching system can be demonstrated by injecting an ink suspension through the mouth and pharynx by means of a hypo- dermic syringe. Then it can be seen that the many branches of the digestive cavity pene- trate to all parts of the both1 (Fig. 16-5).. 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 Marsland, Douglas, 1899-. New York, Holt, Rinehart and Winston
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Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectbiology
