### Theory:

He gave a great leap
And he landed flat
In the crook of the tree-trunk —
Right on the cat!

The cat gave a yell;
And sprang to the ground,
Safe and sound
Explanation:

Stanza $$11$$ tells how the child's father ultimately climbed the tree and landed in the cat's place with a huge leap (amid the tree).

The cat became frightened and cried. It jumped from the tree. Stanza $$12$$ ends with the cat landing safely and happily on the ground. At last, this incident ultimately resolved the problem presented in the initial lines of the poem.