Much larger living Echini are found on this spot.  There is a shell now, more than two inches in diameter.  It is wholly covered with spines half an inch in length.  Radiating from a common centre, flexible at the base, they stand erect at right angles with the shell when the Urchin is in health; but in disease or death order is lost, and they lie across each other in great confusion.  Their connection with the shell is very remarkable, for it is by a ball-and-socket joint,—­the same articulation which gives the human hip its marvellous liberty of action.  Between them are five rows of minute holes, and, in life, a transparent, hair-like foot is protruded from each, at the pleasure of the owner.  When disposed to change its situation, it stretches forth those on the side towards which it would go, fixes them by means of the sucker at the tip of each, and, simultaneously withdrawing those in the rear, pulls itself along.

The mouth, placed in the centre of the base, is very large in proportion to the size of the animal.  It is formed of five shelly, wedge-shaped pieces, each ending in a hard, triangular tooth.  The whole mouth is a conical box, called by naturalists “Aristotle’s lantern.”

The shell is hardly thicker than that of a hen’s egg, and is even more fragile.  When the spines are rubbed off, the brioche-like shape is modified, and in place of the depression in the middle of the upper side there is seen a slight prominence.

Mine was a very inoffensive creature.  He occupied the same corner for many weeks, and changed his place only when a different arrangement of stones was made.  He then wandered to a remote part of the tank and chose a new abode.  Both retreats were on the shady side of a stone overhung with plants.  There for months he quietly kept house, only going up and down his hand-breadth of room once or twice a day.  Minding his own business without hurt to his neighbor, he dwelt in unambitious tranquillity.  Had he not fallen a victim to the most cruel maltreatment, he might still adorn his humble station.

As he was sitting one evening at the door of his house, bending about his lithe arms in the way he was wont, two itinerant Sticklebacks chanced to pass that way.  They paused, and, not seeing the necessity for organs of which they had never known the use, they at once decided on their removal.

In vain did the poor Hedgehog oppose them.  With all the pertinacity of ignorance, they maintained their certainty of his abnormal condition; and with all the officiousness of quackery, they insisted upon immediate amputation.  Aided by two volunteer assistants, the self-made surgeons cut off limb after limb before their reckless butchery could be stopped.

At last I effected their dismissal.  But their pitiable patient was too far reduced for recovery.  His exhausted system never rallied from the shock, and he survived but a few days.

Alas! alas! that so exemplary a member of the community should have perished through piscine empiricism!