“Do you see any change?” he asked.
“Yes,” said Tom, “they have two things like hind legs growing out.”
“These are legs,” his uncle said, “and in two weeks from now these legs will have movable joints in them.”
Day by day the tadpoles were carefully watched, and the following wonderful changes were observed.
When about seven weeks old, their hind legs became jointed, and long toes were formed. The tadpoles were now able to kick out and swim by means of their long hind legs. Their gills went away, and they came to the surface and took mouthfuls of air. They now had lungs instead of gills.
But the most striking change came at the end of the eleventh week.
One by one they lost the cloak which covered head and body.
Under this cloak a pair of fore legs had been folded up and hidden for some time. They were now tiny, wide-mouthed frogs, with long, clumsy tails.
The clumsy tails grew smaller and smaller daily. At last there was no tail left, and what was at one time a cluster of black, wriggling tadpoles, was now a crowd of lively little dark yellow frogs.
The boys wished to keep them longer, but their uncle told them that they could not do this.