ON THE DIGESTIVE ORGANS, AND THEIR APPENDAGES. 127 



In all herbivorous Mammalia the stomach is enormous, often highly 

 complicated, and the intestinal canal long : the material necessary for 

 the support of the system is not only very considerable in quantity, but 

 it requires to be ground to a fine pulp before its proper digestion can 

 be accomplished. In fish-eating animals, as the Porpoise and Dolphin, 

 the = stomach is complex, and the intestinal canal long, but simple. 

 These animals are necessarily voracious : their digestion is rapid ; but 

 the cold-blooded prey, upon which they feed, yields a less proportion 

 of nutriment, relatively to the quantity of material swallowed, than does 

 the flesh of hot-blooded vertebrata, on which the true Carnivora, for 

 the most part, feed ; so that these animals, destructive as they are, are 

 less voracious than are piscivorous Mammalia : the Tiger destroys life to 

 a far less amount than the Porpoise or Seal. 



The mouth, as already observed, is to be regarded as the commence- 

 ment of the digestive apparatus : its posterior part, above, is bounded, par- 

 tially, by a fleshy curtain, termed the soft palate, or velum pendulum 

 palati. In the human subject, and the Chimpanzee, the apex of the 

 velum forms a small projecting glandular body, termed the uvula. From 

 each side of the uvula, the velum passes downward, in the form of a 

 double arch, on each side : the anterior arch sweeping from the base of 

 the uvula to the root of the tongue ; the posterior, to the side of the pha- 

 rynx. In the fleshy space between these arches lie the tonsils, certain 

 glands, which secrete a lubricating fluid. The common opening, between 

 the anterior and posterior arch, viz., the space bounded above by the soft 

 palate, is termed the fauces, or Isthmus faucium ; the posterior orifice of 

 which (capable, as may be seen, of being dilated or contracted) opens into 

 the pharynx, or wide commencement of the oesophagus. Into the fauces 

 opens the glottis, or entrance of the larynx,* of which the trachea, or 



* The larynx, or vocal organ, is the commencement of the trachea, or windpipe, and consists of 

 several cartilages: viz., the thyroid cartilage, forming its anterior part, and its largest portion, and 

 placed immediately below the os hyoides ; the cricoid cartilage, situated immediately below the thyroid 

 and the first cartilaginous ring of the trachea, and generally forming a semicircular band two arytenoid 

 cartilages, which are small, and supported on the posterior upper edge of the cricoid, and between the 

 two wings of the thyroid. These two cartilages form, between themselves and the thyroid, a longitudinal 

 fissure, extending from before/.backward, which is called the glottis, or rimaglottidis. From the arytenoid 

 cartilages on each side, to the thyroid, anteriorly passes a ligamentous expansion, narrowing the fissure 

 of the glottis, which, by the action of delicate muscles, may be widened or contracted : these ligaments 

 are termed the chordae vocales, or vocal chords ; they regulate the intonation of the voice, and modu- 

 late the notes of which it is capable, like the stops upon a flute. The rima glottidis is furnished with a 

 valvular cartilage, termed the epiglottis (present only in Mammalia), of a triangular shape, with a 

 broad base, and situated behind the root of the tongue : under ordinary circumstances it is elevated ; 

 but, in the act of swallowing, it is drawn down by certain small muscles, so as to fold over the rima, 

 the sides of which are, at the same time, closed together, in order that the food may pass over 

 without entering the larynx, an accident which sometimes happens. The trachea, or windpipe, is 

 continued from the larynx, and consists of a series of cartilaginous rings, imperfect behind (where the 

 larynx and oesophagus are in contact), invested with an external and internal lining, which form the 

 interspace between each ring. An inspection of the trachea of the Sheep, or Ox, will render this 

 explanation easily understood. 



