. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 3BS MONOTREMATA. Fig. Thoracic and abdominal viscera, Ornithorhynchus. (Meckel.) Echidna is unprovided with teeth; but the palate is armed with six or seven transverse rows of strong, sharp, but short retroverted spines. The tongue is long and slender as in the true Anteaters ; its dorsum is broad, flat, callous, and beset with hard papilla, and the insects are doubtless crushed and lacerated between the?e and the pa'atal spines. As, how- ever, the food undergoes less comminution in the mouth of this Monotreme than
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 3BS MONOTREMATA. Fig. Thoracic and abdominal viscera, Ornithorhynchus. (Meckel.) Echidna is unprovided with teeth; but the palate is armed with six or seven transverse rows of strong, sharp, but short retroverted spines. The tongue is long and slender as in the true Anteaters ; its dorsum is broad, flat, callous, and beset with hard papilla, and the insects are doubtless crushed and lacerated between the?e and the pa'atal spines. As, how- ever, the food undergoes less comminution in the mouth of this Monotreme than in that of the Ornithorhynchus, the pharynx and oesophagus are wider, and a dense epithelium lines the inner surface of the latter tube, and is conti- nued over the capacious stomach to the py- lorus, near which orifice it is developed into numerous horny and sharp papillae. The sub- jacent mucous membrane is smooth; the tunics of the stomach are very thin, except at the pylorus, which forms a prominent protuberance in the duodenum. The intestinal canal of the Echidna is seven times the length of the bodv; the mucous membrane is not raised into val- vular folds; a small vermiform and glandular ccecum divides the small from the large intes- tines ; the rectum terminates as in the Ornitho- rhynchus. Salivary glands.—There appears to be no parotid gland in the Echidna, and it is doubt- ful whether the thin flat stratum of glandular substance (Jig. 180, £), which extends from the meatus auditorius to the check-pouch in the Ornithorhynchus, can be so regarded. The submaxillary gland (Jig. 180, JD) is a mode- rately-sized, oval, compact body, situated be- hind and below the meatus auditorius; it mea- sured five lines in the long diameter and four in the short diameter. The duct is very small, scarcely admitting an absorbent injecting pipe; it passes under the omo-mylo-hyoideus(10),and then, contrary to the usual mode, begins to be disposed in a series of about twelve close trans
Size: 1002px × 2495px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, booksubjectanatomy, booksubjectphysiology, booksubjectzoology
