His uncle looked, and saw that the white patches of eggs had given place to larger patches of little active, dark coloured maggots.
“We want to know what has become of the lovely carved shells of the eggs,” said Tom.
“They have been eaten up,” his uncle replied. “From the moment a caterpillar is born he does nothing but eat—eat—eat. He begins by eating the shell of the egg he comes out of.
“For the first week of their lives these tiny caterpillars feed together in small bands, and they grow so fast you can almost fancy you see them growing. After they have grown to a certain size, each caterpillar starts out for himself.”
“Do you see the three butterflies that have hatched out?” asked Tom.
“Yes, I see them. There are two females and one male,” said Uncle George.
“How can you tell males from females?” asked Frank.
“Oh, that is easy enough,” Uncle George replied. “The females are larger, and have two big black spots on each of their front wings. But I only see eight of the large cabbage caterpillars. We put in twelve, I think.”
“Look!” said Frank, pointing to the roof of the cage.
“Ah, yes, I see them. Two of them have passed into the pupæ stage, and are slung up by their silken belts to the wall of the cage.