TADPOLES. 21 
to fade, and, little by little, withers away, until in the perfect animal 
it entirely disappears. About the same time the lungs become de- 
veloped, and assume their functions. In Fig. 5 may be traced 
the successive phases ofits transformation from the egg to the tad- 
Fig. 5.—Development of the Tadpole. 
1, Egg of the Frog. 2. The egg fecundated, and surrounded by its visicule. 3. First state of 
the Tadpole. 4. Appearance of the breathing gills. 5. Their development. 6. Formation. 
of the hind feet. 7. Formation of the fore feet, and decay of the gills. 8. Development of 
the lungs, and reduction of the tail 9. The perfect Frog. 
pole, till we finally reach the perfect Batrachian. Through these 
admirable modifications we see the fish little by little becoming a 
Batrachian. In order to follow this strange metamorphosis, it 
suffices to gather some Frogs’ eggs, and place them with some 
aquatic herbs in an aquarium, or in a globe with gold and silver 
fish. It there constitutes a most interesting spectacle, and we 
