168 ANIMAL PHYSIOLOGY. [LESSON 48. 



From this point, a short intestine (e, e) arises, which opens into the 

 cloaca (/). The soft roe (h, h) of the male fish, like the ovarium of 

 the female, empties its contents through the common duct (i), and 



FIG. 268. 



Nutrimental organs, Herring. 



finally by the aperture (k) beyond the cloacal outlet (/). This one 

 figure is a sufficient demonstration of the general arrangement of the 

 nutrimental organs in the class of Fishes ; the modifications to which 

 it is subject being too unimportant to need comment : we therefore 

 proceed to the class of 



REPTILES. 



737. These animals, like the Fishes, are predaceous in their 

 habits, and swallow their prey whole. They have loose and feeble 

 articulation of the jaws, which greatly favors such proceeding, while 

 their teeth are sharp, slender, and fitted as prehensile organs, but ill 

 adapted to the purposes of mastication. 



738. The long, free bifid tongue of the Frog, covered with pa- 

 pillae, and muciparous (mucous) follicles, is the all important instru- 

 ment for the procuration of food. 



739. It is attached by its apex to the inner surface of the under 

 jaw, the base being loose and free in the back part of the mouth. 

 A Frog will never touch any save a living insect, and of this fact it 

 requires such positive and conclusive evidence, that the latter often 

 escapes before the former is sufficiently stimulated to attempt its 

 capture. 



"When once a Frog fixes his eye on a lively living insect, his whole 

 appearance is suddenly changed. The passive, sluggish animal of 

 the minute before, has suddenly assumed the aspect of ferocity. 



740. If it be a fly at some distance from the frog, on the carpet, 

 the latter, his eyes full of malignity and craft, stretches out his 



