THE FROG. 



PLATE II. 



THE FROG-. THE ALIMENTARY, RESPIRATORY, AND UBINO-GENITAL ORGANS. THE HEART. 



THE LYMPH-HEARTS, ETC. 



FIG. I. The entire alimentary apparatus, after removal from the body, dissected from 

 the ventral aspect. 



The lower jaw was pinned back, and the interior of the right vocal sac exposed ; the 

 stomach, duodenum, cloaca, and bladder were each opened up. $. x 2. 



The bile-ducts can readily be demonstrated, by gently squeezing the gall-bladder and 

 thus forcing the bile into them. For a full description, with figures, of the smaller hepatic 

 ducts and of the valve-like arrangement of the lining membrane of the small intestine, in 

 Rana esculenta, see Wiedersheim and Ecker (24). 



FIG. II. A portion of Fig. I., after removal of the liver, x 1. 



The lymph-sinus drawn can be readily inflated by introducing a blow-pipe under the 

 peritoneum. 



FIG. III. The respiratory segment of Fig. I. 



The right lung was opened up, to show its internal structure, x !. 



FIG. IV. The left lung of the same, with the larynx seen from the side. 



FIG. V. The same, after removal of the left lung together with one half of the larynx. 



FIG. VI. The cartilages of the larynx dissected out. 

 Seen from the front. All x li. 



FIGS. VII. and VIII. The lymph-hearts, x 1. 



The posterior one, Fig. VIII., is to be seen on removing the skin of the back, imme- 

 diately after death, and the anterior one by making a clean cut along the ventral body- 

 wall to one side of the middle line and a similar one into the cisterna magna, turning the 

 stomach to one side as indicated. Only such parts are drawn as are indispensable in 

 determining the positions of these delicate organs. 



Certain details, as to the connections of the above with the great veins, are figured by 

 Ranvier (19). 



. IX. The heart, after removal from the body. 

 Seen from the front, the aortic arches of the left side having been removed, x 4. 



FIG. X. The same from behind, the sinus venosus having been opened up, to show 

 the sinu- auricular valves. x 4. 



