7 6 



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.E T H ' 



\crih W(A n. a . f \*Jy* 



:H\_ a 1 - 1 rrirnruFMir\TTT- , 



PMX 



vo. 



MLMCK 



s.iril 



FlG. 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; 

 cblm, cerebellum ; cl, cloaca; en. j, centrum of third vertebra; cp. ad, 

 corpus adiposum ; crb. /i, cerebral hemisphere; d. ly. s, dorsal lymph 

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

 FR. PA, fronto-parietal ; gj, glottis; git I, gullet; IL, ilium ; is, ischium ; 

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

 meckelian ; n. a. i, neural arch of first vertebra; olf. I, olfactory lobe; 

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

 premaxilla ; /;;, pancreas ; p. na, posterior naris ; pit, pubis; ret, rec- 

 tum ; r. Ing, right lung; J-. hit, small intestine; sp. cd, spinal cord; SPH. 

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

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

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

 teeth ; vs. sent, 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 



