The Burgess Animal Book For Children in "More Of Peter's Long-legged Cousins"

But he does take to it as the easiest way of getting rid of those who are chasing him.
The Marsh Rabbit and the Swamp Hare are the only members of your family in all the Great World who are fond of the water and who are at home in it. Now, who shall I tell you about?"

"Our biggest cousins," cried Ryder and Jumper together. "The ones you told us yesterday are bigger than Jumper," added Ryder.