XIII 



PHYLUM CHORDATA 



257 



bodies, their bases ankylosed to the bones ; their only use is Ho 

 prevent the polished or slimy bodies of the prey- -Insects and 

 Worms from slipping out of the mouth. 



The buccal cavity narrows towards the plianjnx, which leads by 

 a short gullet (gul) into a stomach (sf) 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 



IL 



P.VX 



vo.l 



M.MCK 



s.int 



FIG. 876. Ranatemporaria. Dissection from the left side ; the viscera somewhat displaced. 

 an. anus ; b. d. bile-duct ; b. Inj. body of hyoid ; bl. urinary bladder ; bl.' its opening into 

 cloaca ; c. art. conus arteriosus ; cblm. cerebellum ; cl. cloaca ; en. 3, centrum of third vertebra ; 

 cp. ad. corpus adiposurn ; crb. li. cerebral hemisphere ; d. l>/. s. dorsal lymph sinus ; du. duo- 

 denum ; ep.cor. epicoracoid ; ens. t. Eustachian tube ; FR. PA. fronto-parietal ; gl. glottis ; 

 fie/, gullet ; IL. ilium ; is. ischium ; kd. kidney ; 1. at', left auricle ; I. Ing. left lung ; //. liver ; 

 M. MCK. meuto-meckeliau ; n. a. 1, neural arch of first vertebra ; olf. I. olfactory lobe ; opt. I. 

 optic lobe ; o. ST. omo- and epi-stemum ; pcd. pericardium ; PMX. premaxilla ; pn. pancreas ; 

 p. /?. posteiior uaris ; pu. pubis; ret. rectum ; r.lng. right lung; s.int. small intestine; 

 sp. cd. spinal cord ; SPH. ETH. sphenethmoid ; spl. spleen ; st. stomach ; s. v. sinus venqsus ; 

 liift. tongue; ts. testis ; ur. ureter; ur.' its aperture into the cloaca; UST. urostyle ; ^ven- 

 tricle ; v. ly. s. ventral lymph sinus ; ro. t. vomerine teeth ; vs. sem. vesicula seminalis. 



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

 without change of diameter into the cloaca (cl). 



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

 lies a large gall-Uadder (Fig. 877, G). The pancreas (P) is an 

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

 secretion ; the spleen (Fig. 876, 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 lies behind and below the 

 tympanic membrane. 



Respiratory Organs.- -The lungs (1. Ing, r. Ing) are elastic sacs 

 lying in the anterior part of the coelome above the heart and liver ; 

 their size and appearance vary greatly according to their state 

 of distension. Each contains a spacious cavity and has its walls 



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