XIII 



PHYLUM CHORDATA 



277 



The buccal cavity narrows towards the pharynx, which leads by 

 a short gullet (gid.) into a stomach (st.) consisting of a wide cardiac, 

 and a short, narrow, pyloric division. The duodenum (du), or first 

 portion of the small intestine, passes forwards parallel with the 

 stomach ; the rest of the small intestine is twisted into a coil. The 

 large intestine or rectum (ret.) is very wide and short, and passes 

 without change of diameter into the cloaca (el.). 



The liver (Ir.) is two-lobed ; between the right and left lobes 

 lies a large gall-bladder (Fig. 930, G). The pancreas (P.) is an 

 irregular gland surrounding the bile-duct, into which it pours its 



Fio.930.— Banaesculenta. Stomach and duodenum with liTer and pancreas. Vc, Pc.lcommon 

 bile duct ; i)c.2 its opening Into the duodenum ; V. cy. cystic ducts ; Bh., Bh.i hepatic ducts ; 

 Bu. duodenum ; O. gall-bladder ; L, U, 1?, I^, lobes of liver, turned forwards ; Ihp. duodcno- 

 hepatic omentum, a sheet of peritoneum connecting the liver with the duodenum ; M, 

 stomach ; P. pancreas ; Pl, pancreatic duct ; Py. pylorus. (From Wiedorsheim's Coviparative 

 Anatmny.) 



secretion ; the spleen (Fig. 929, spl.) is a small, red, globular body 

 attached near the anterior end of the rectum. The thyroids are 

 small paired organs lying below the floor of the mouth in front of 

 the glottis. The thymus is also paired, and is situated behind and 

 below the tympanic membrane. 



Respiratory Organs. — The lungs (I. Ing., r. Ing.) are elastic sacs 

 lying in the anterior part of the ccelome above the heart and liver : 



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