THE ALIMENTARY CANAL AND ITS APPENDAGES. 335 



(8 to 20), some of which join the submaxillary duct, while 

 the rest open separately in the floor of the mouth. 



The Fauces is the name given to the aperture which can 

 be seen at the back of the mouth below the soft palate (Fig. 

 105), and leading into the pharynx. It is bounded above by 

 the soft palate and uvula, below by the root of the tongue, 

 and on the sides by muscular elevations covered by mucous 

 membrane, which reach from the soft palate to the tongue. 

 These elevations are the pillars of the fauces. Each bifur- 

 cates below, and in the hollow between its divisions lies a 

 tonsil (7, Fig. Ill), a soft rounded body about the size of an 

 almond, and containing numerous minute glands which form 

 mucus. 



The tonsils not unfrequently become enlarged during a 

 cold or sore throat, and then pressing on the Eustachiau tube 

 (Chap. XXXIV), which leads from the pharynx to the mid- 

 dle ear, keep it closed and produce partial deafness. 



The Pharynx or Throat-cavity (Fig. 105). This por- 

 tion of the alimentary canal may be described as a conical 

 bag with its broad end turned upwards towards the base of 

 the skull, and its narrow end downwards and passing into the 

 gullet. Its front is imperfect, presenting openings which 

 lead into the nose, the mouth, and (through the larynx 

 and windpipe) the lungs. Except during swallowing or 

 speech the soft palate hangs down between the mouth and 

 pharynx; during deglutition it is raised into a horizontal 

 position and separates an upper or respiratory portion of the 

 pharynx from the rest. Through this upper part, therefore, 

 air alone passes, entering it from the posterior ends of the 

 two nostril- chambers; while through the lower portion both 

 food and air pass, one on its way to the gullet, b, Fig. 105, 

 the other through the larynx, d, to the windpipe, c\ when 

 a morsel of food " goes the wrong way " it takes the latter 

 course. Opening into the upper portion of the pharynx on 

 each side is an Eustachian tube, g: so that the apertures 

 leading out of it are seven in number; the two posterior 

 nares, the two Eustachian tubes, the fauces, the opening of 

 the larynx, and that of the gullet. At the root of the tongue, 

 over the opening of the larynx, is a plate of cartilage, the 

 epiglottis, e, which can be seen if the mouth is widely opened 

 and the back of the tongue pressed down by some such thing 

 as the handle of a spoon. During swallowing the epiglottis 



