The Grass divides as with a Comb (5)
Hello?! The speaker almost stepped on a snake, but isn’t fazed. He quickly moves on to observe the grass as the snake moves away. Not us. We would have freaked out if that happened.
It wrinkled And was gone— (16)
When things disappear into thin air, this is scary. Here we have another example of the speaker's vision failing to render the world for what it really is.
Without a tighter Breathing And Zero at the Bone (23-24)
This is a great description of the “fight or flight response.” In the speaker's case, we're guessing flight. It seems that the experience of these snake encounters is just too much for his fragile grasp on reality.