76 



THE BIOLOGY OF THE FROG 



CHAP. 



are greatly enlarged, and may be recognized by the small, 

 globular, dark-colored eggs which form the greater part of 

 their mass. External to the ovaries are the large, white con- 



^'^^ 



SPH.f^H 



«. \dlyAsp.cd ^^F ^ kdj^^^ I ^, 



Fig. II. — Rana temporaria. Dissection from the left side; the viscera 

 somewhat displaced, an, anus; b. d, bile duct; b. hy, body of hyoid ; 

 bl, urinary bladder; bl' , its opening into cloaca; c. art, conus arteriosus; 

 ^(^/w, cerebellum ; cl, cloaca; tv/. j, centrum of third vertebra; cp. ad, 

 corpus adiposum ; ^r*^. /^, cerebral hemisphere; ^. /j'. j, dorsal lymph 

 sinus; du, duodenum; ep. co7-, epicoracoid ; ens. t. Eustachian tube; 

 FR. PA, fronto-parietal ; gl, glottis; giil, gullet; IL, ilium ; IS, ischium ; 

 kd, kidney; /. an, left auricle; /. big, left lung; Ir, liver; M. MCK, mento- 

 meckelian ; n. a. i, neurnl arch of first vertebra; o/f. I, olfactory lobe; 

 opt. I, optic lobe ; O. sr, omo- and epi-sternum ; pcd, pericardium ; PMX, 

 premaxilla ; pn, pancreas ; p. tia, posterior naris ; pu, pubis ; ret, rec- 

 tum ; r. I>ig, right lung; s. hit, small intestine; sp. cd, spinal cord; SPH. 

 ETH, sphenethmoid; spl, spleen ; st, stomach ; s. v, sinus venosus; tug, 

 tongue; ts, testis; ur, ureter; ur' , its aperture into the cloaca; UST, 

 urostyle; v, ventricle; v. ly. s, ventral lymph sinus; vo. t, vomerine 

 teeth ; vs. sem, vesicula seminalis. 



voluted tubes, the oviducts. These are also suspended to the 

 dorsal body wall by thin sheets of membrane ; they have no 

 connection with the ovaries ; anteriorly they open into the 



