Their ribs is like wash-boards, an' their stomachs is right up against their backbones.

They're pretty desperate, I can tell you.

They'll be goin' mad, yet, an' then watch out." A few minutes later, Henry, who was now travelling behind the sled, emitted a low, warning whistle.

Bill turned and looked, then quietly stopped the dogs.

To the rear, from around the last bend and plainly into view, on the very trail they had just covered, trotted a furry, slinking form.