A frog hunts on land by vision. He escapes
Enemies mainly by seeing them. His eyes
Do not move, as do ours, to follow prey,
Attend suspicious events, or search
For things of interest. If his body changes
Its position with respect to gravity or the whole
Visual world is rotated around him
Then he shows compensatory eye-movements. These

Movements enter his hunting and evading
Habits only, e.g. as he sits
On a rocking lily pad. Thus his eyes
Are actively stabilised. The frog does not seem
To see, or at any rate is not concerned with
The detail of the stationary world around him.
He will starve to death surrounded by food
If it is not moving. His choice of food
Is determined only by size and movement.
He will leap to capture any object the size
Of an insect or worm provided if it moves
Like one. He can be fooled easily not only
By a piece of dangling meat but by any
Small moving object. His sex life
Is conducted by sound and touch. His choice
Of paths in escaping enemies does not

Seem to be governed by anything more devious
Than leaping to where it is darker. Since
He is equally at home on water and on land,
Why should it matter where he lights
After jumping, or what particular direction
He takes? He does remember a moving
Thing provided it stays within
His field of vision and he is not distracted.

May 28 1969