1. He watched them fly, their color a bright slash in solid green, and in this way he found the berries
What does slash mean here?
2. His whole abdomen was torn with great rolling jolts of pain, pain that doubled him in the darkness of the little shelter, put him over and face down in the sand to moan again and again: "Mother, mother, mother..."
What do "rolling", "jolts", "double" mean here?
3. It was as if all the berries, all the pits had exploded in the center of him, ripped arid tore at him.
What does "rip arid tore at" mean here?