burrows bolt-holes in the beaches, is by no means an uninteresting
character. Surrounded by enemies, and yet living on the bare, coverless
beach, its faculties for self-preservation are exceptionally refined.
The eyes are elongated ovals, based on singularly mobile pivots, while
the pupils resemble the bubble of a spirit-level. Not only is the range
of vision a complete circle, but the crab seems able to concentrate its
gaze upon any two given points instantly and automatically. To spite all
its skill as a digger, to set at naught its superb visual alertness, the
sand crab has a special enemy in the bird policeman which patrols the
beach. Vigilant and obnoxiously interfering, the policeman has a long and
curiously curved beak, designed for probing into the affairs of crabs,
and unless the "hatter" has hastily stopped the mouth of its shaft with
a bundle of loose sand--which to the prying bird signifies "Out! Please
return after lunch!"--will be disposed of with scant ceremony and no
grace, for the manners of the policeman are shocking.

This quick-footed sand-digger enhances its reputation by the performance
of feats of subtlety and skill. Its bolt-hole is sometimes three feet
deep, generally on an incline. Piled in a mound the spoil would
inevitably betray the site of the operations to the policeman, thus
seriously facilitating the duties of that official towards the
suppression of the species. From remote depths the crab carries a bundle
of sand. You remember the trenchant way in which Pip's sister cut the
bread and butter, her left hand jamming the loaf hard and fast against
her bib? Just so the crab with its bundle of loose sand, though it has
the advantage in the number of limbs which may be pressed into service.
The feat of carrying an armful of sliding sand in proportion to bulk
about one-third of the body, is far away and beyond the capacities of
human beings, but to the crab, which has acquired the trick of temporary
consolidation by pressure, it is merely child's play. Arrived at the