Do frogs have lungs or gills?
The life story of the frog is astounding. During his kindergarten days, he wears a fringe of feathery gills where his neck should be. Later, he exchanges his fishy gills for a pair of lungs in his chest. During his lifetime he has both gills and lungs, but not both at the same time. A grown frog spends his time in and out of the water. He sits for hours beside his swimming pool, enjoying the warm sun and using the lungs in his chest to breathe in and breathe out. Suddenly he leaps up in a fancy high dive and plunges down into the pond. After a few splendid swimming strokes under water, he may decide to settle for awhile on the bottom. And there he squats for five minutes, ten minutes or even an hour. Surely he cannot be holding his breath all this time. No, he is not. He is getting a constant supply of oxygen from the water. Lungs, of course, are made for taking oxygen from the air and under water they are useless. Fishes and many other animals have gills made specially to sift oxygen
