A narrow fellow in the grass

A narrow fellow in the grass
Occasionally rides;
You may have met himdid you not?[^a1]
His notice instant is,
The grass divides as with a comb,
A spotted shaft is seen,
And then it closes at your feet,
And opens further on.

[^a1: not? | not]

He likes a boggy acre,
A floor too cool for corn,
Yet when a boy and barefoot,
I more than once at noon
Have passed, I thought, a whip-lash[^a2],
Unbraiding in the sun,
When stooping to secure it,
It wrinkled and was gone.

[^a2: whip-lash | whip lash]

Several of nature's people
I know, and they know me;
I feel for them a transport
Of cordiality.
Yet never met this fellow,
Attended or alone,
Without a tighter breathing,
And zero at the bone.