268 



ZOOLOGY 



SECT. 



or to their form, e.g. biceps, the two-headed muscle ; or to their 

 action, e.g. flexor tarsi ; or to their origin and insertion, e.g. coraco- 

 humeralis. 



Digestive Organs. The mouth leads into a wide buccal cavity 

 having in its roof the internal or posterior nares (Fig. 940, p. na.), 

 a pair of projections due to the downward bulging of the large 

 eyes, and the openings of the Eustachian tubes (eus. t., vide infra). 

 On its floor is the large tongue (tng.), attached in front and free 

 behind, where it ends in a double point ; by means of its muscles 

 it can be suddenly projected, point foremost, from the mouth, and 

 is used in the capture of Insects. Immediately behind the tongue 

 is the glottis (gl.). Teeth are arranged in a single series round the 

 edge of the upper jaw, attached to the premaxillse and maxillae ; 



IL 



PMX 



si nt 



FIG. 940. Rana temporaria. Dissection fromjthe left side ; tlie viscera somewhat displaced. 

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

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

 bra ; cp. ad. corpus adiposum ; c rb. h. cerebral hemisphere ; d. ly. s. dorsal lymph sinus ; du. 

 duodenum ; ep. cor. epicoracoid ; cus. t. Eustachian tube ; FR. PA. fronto-parietal ; gl. 

 glottis ; rjul. gullet ; IL. ilium ; is. ischium ; kd. kidney ; /. au. left auricle ; /. Ing. left lung ; 

 Ir. liver ; M. MCK. mento-meckelian ; n. a 1, neural arch of first vertebra ; olf. I. olfactory 

 bulb ; opt. 1. optic lobe ; q. ST. omosternum ; pcd. pericardium ; PMX. premaxilla ; 

 pn. pancreas ; p. na. posterior naris ; pu. pubis ; ret. rectum ; r. Ing. right lung ; s. int. 

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

 venosus ; tng. tongue ; ts. test-is ; ur. ureter ; ur' . its aperture into the cloaca ; TJST. urostyle ; 

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



there is also a small patch of teeth (vo. t.) on each vomer just 

 internal to the posterior nostril. The teeth are small conical 

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

 prevent the polished or slimy bodies of the prey Insects and 

 Worms from slipping out of the mouth. 



The buccal cavity narrows towards the pharynx, which leads by 

 a short gullet (gul.) 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 (iteum) is twisted into a 



