Helen, the verse I remember from childhood is:

One day as I was walking by
I saw a birdy flying high
He dropped a message from the sky,
And as I wiped it from my eye
I thank the Lord the cows don't fly!

and of course:
Peanut sitting on the railway line
His heart was all a-flutter
Train came roaring round the bend
Toot toot peanut butter!

Cheers
JennieG