XIII 



PHYLUM CHORDATA 



431 



Eustachian tubes. The nasal division is continuous with the- 

 buccal division round the posterior free edge of the soft palate. 

 From the buccal division leads ventrally the slit-like opening of 

 the glottis l into the larynx and trachea ; overhanging the glottis 

 is a leaf-like movable flap (Fig. 1025, ep.) formed of a plate of 

 yellow elastic cartilage covered with mucous membrane ; this is 

 the epiglottis. Behind the pharynx becomes continuous with 

 the oesophagus or gullet (oes.). The latter is a narrow but dilatable 

 muscular tube, which runs backwards "from the pharynx through 



cbl 



FIG. 1025. Lepus cuniculus. Lateral dissection of the head, neck and thorax. The -head 

 and spinal column are represented in mesial vertical section ; the left lung is removed ; the 

 greater part of the nasal septum is removed so as to show the right nasal cavity with its 

 turbinals. aort. dorsal aorta; b.hy, basi-hyal ; cbl. cerebellum; a:,: cerebral hemispheres; 

 cor. v. coronary vein ; <lia. diaphragm ; ep. epiglottis ; eu. opening of Eustachian tube into 

 pharynx ; lar. larwix ; t. '/. >.: left jugular vein ; L .<6. a. left subclavian artery ; 1. sb. v. left 

 subclavian vein ; IIMX. maxilla : niaL medulla ; mes.eth. mesethmoid ; mx.trb. maxilla-turbinal ; 

 o;s. oasophagus ; olf. olfactory lobe ; pi. a. pulmonary artery ; p.max. pre-maxilla ; pr.st. pre- 

 sternum ; pt.c. post-caval vein ; rt.lng. root of left lung with bronchus and pulmonary veins 

 and artery cut across ; ,. gl. sub-lingual salivary gland ; s.m:e. gl. sub-maxillary salivary gland ; 

 st. sternebrte ; tng. tongue tr trachea ; trb. ethmo-turbinals ; vel. pi. soft palate. 



the neck and thorax to enter the cavity of the abdomen through 

 an aperture in the diaphragm, and opens into the stomach. 



The stomach (Fig. 1026) is a wide sac, much wider at the end 

 (cardiac), at which the oesophagus enters, than at the opposite or 

 pyloric end, where it passes into the small intestine. The small 

 intestine is an elongated, narrow, greatly coiled tube, the first 

 part of which, or duodenum (d/u, and du'), forms a U-shaped loop. 

 The large intestine is a wide tube, the first and greater part of 

 which, termed the colon, has its walls sacculated, a structure which 

 is absent in the short, straight posterior part or rectum (ret.). At 

 the junction of the small with the large intestine is a very wide 

 blind tube, the caecum, which is of considerable length and is 



1 The term glottis is more strictly applied not to this slit, but to the entire' 

 passage from the pharynx to the trachea. 



