The continual introduction of the landscape to be seen from his refuge knits the discursive thinking of the savage into a kind of unity.

We watch him lying in the thick water-slime of the hollow, his head on the rim of it propped by his hands, under the cave's mouth, hidden by the gadding gourds and vines; looking out to sea and watching the wild animals that pass him by--and out of this place he does not stir.
In Shakespeare's _Tempest_ Caliban is the gross, brutal element of the earth and is opposed to Ariel, the light, swift, fine element of the air.

Caliban curses Prospero with the evils of the earth, with the wicked dew of the fen and the red plague of the sea-marsh.

Browning's Caliban does not curse at all.

When he is not angered, or in a caprice, he is a good-natured creature, full of animal enjoyment.