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THE FROG. PHYLUM CHORDATA 



fJIT. 



Fig. 281. — A male frog dissected from the ventral side. 



a.ah.v., .interior abdominal vein, cut short, ligatured, and turned back ; a. muse, cut edge of abdominal 

 muscles ; bl., urinary bladder ; c.d., common duct of gall-bladder and pancreas ; d.ao., dorsal aorta ; 

 du., duodenum ; f.b., fat body ; fem.v., femoral vein ; g.b., gall-bladder ; ht., heart ; hy.n., hypoglossal 

 nerve ; im., ileum ; i.ii.c, inferior vena cava ; k., kidney ; k.d., kidney duct with vesicula seminalis; 

 Ir., liver ; o., point at which c.d. enters the duodenum ; pes., pancreas ; pl.v., pelvic vein ; r.l., right 

 lung ; rm., rectum ; r.p.v., renal portal vein ; sar., sartorius muscle ; sm., mylohyoid muscle ; sp., 

 spleen ; St., stomach ; t., testis ; v. v., vesical vein. 



jaw is a region known as the pharynx, into which open, at the 

 sides of its roof, the pair of Eustachian tubes which lead to the 

 drums of the ears, and below, in the male, a pair of vocal sacs 

 which are inflated and act as resonators during croaking. In the 



