. Cassell's natural history. Animals; Animal behavior. be cephalic ganglion; (, cesophageal ganglion* sends forward trvo dis- tinct chords, which are united by a connnissure or cross nerve behind the oesophagus, and have each a small ganglion on either side which gives off nerves to the mandibles, the stomach, the heart, the liver, and the intestines. These chords then unite once more in a single large ganglion in front of the mouth, and hence called the svpra- oxopliKgeal ganglion. This is the Lobster's brahi^ and its nerves go to the feelers, the eyes, and the other sensual organs of the ani
. Cassell's natural history. Animals; Animal behavior. be cephalic ganglion; (, cesophageal ganglion* sends forward trvo dis- tinct chords, which are united by a connnissure or cross nerve behind the oesophagus, and have each a small ganglion on either side which gives off nerves to the mandibles, the stomach, the heart, the liver, and the intestines. These chords then unite once more in a single large ganglion in front of the mouth, and hence called the svpra- oxopliKgeal ganglion. This is the Lobster's brahi^ and its nerves go to the feelers, the eyes, and the other sensual organs of the animal. Above the- nervous system is the alimentary canal, or the great duct or intestine by whicli the functions of digestion and nutrition are carried on. We have already seeil with what an array o£ , , foot-jaws, jaws, and mandibles, for cutting, crushing, tearing, biting, and generally pulling to pieces, a Lobster's mouth is armed ; but, as if still further to insure perfect digestion, the stomach itself is provided with a set of calcai-eous teeth covered with strong ridges like the grinding surface of the tooth of a small Eodent or Kan- garoo Eat. These gastric teeth (Fig. 7) triturate the food against a fixed calcareous ridge, also set in the wall of the stomach, and are moved by apjjropriate muscles. In the lower chamber of the stomach, leading to the intestine, and named the pylorus, a series of fine hai'-s are placed, which prevent the escape of the coarser particles of food, until they have been repeatedly subjected to the molar-like action of these gastric teeth. Tlie liver in both the Crab and Lobster is a very large and highly complex organ, not solid like the human liver. The secreted fluid, or bile, is poured by two openings into the pylorus. Imnie- <liately beneath the cephalic .shield of the Lobster lie the heart and the Fip- 7 r.^ teeth of great main artery which supplies the entire length of the body. The heart of a single ventri
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Keywords: ., bookcentury1800, bookdecade1890, booksubjecta, booksubjectanimals
