When they are about a month old they begin to feel that life has its realities, and that they must do something towards the end for which they were made.  The thought is faint at first, but by degrees grows weightier, till at last they can stand it no longer, and, making a great effort to throw off the incubus of babyhood that weighs so heavily upon them, they burst open the back door of their shell and slowly creep out backwards.  It takes about five minutes for them to get entirely out, head, legs and all, and then for a moment or two they gaze in stupefaction at their old shell, amazed to find that they have, by their own efforts, unaided and alone, accomplished such a wonderful change.

The thought is overwhelming.  It fills them with pride; rejoicingly they exult, and swell with gratification.  This state of self-gratulation lasts about twenty minutes, at the end of which time they have increased their bulk to nearly double its former size, and they remain so.

They can’t get back into the old shell now, for it won’t fit them, and as there is no other for them to go into, the only thing left for them to do is to build another house.

It takes three or four days before they get fairly to work, and during this time they are called soft-shell crabs.  This stage is particularly dangerous to the delicate creatures, for they, in their tender beauty, are so attractive to hungry fishes that it is really a wonder any escape.  Tender, helpless, innocent and beautiful, they are almost sure to be victimized and gormandized.

Some, however, escape the fate intended for them, and in a few days begin to enjoy life in a crabbed sort of a way.  Another month passes on.  They become restless and uneasy, and feel that it won’t do to stay too long in one place.  They think they had better make another change, and so this time, in a more self-confident manner, they pack up and move out at the back door again.  They are no more provident now, however, than they were at first, for, after having given up the old house, they have no new one to move into.  They are not troubled as we are with house-hunting; they are good builders, and can make one to suit themselves.  A wise provision of nature, for these interesting creatures are really obliged monthly to go out doors to grow.

This state is to them doubly dangerous.  Mankind they always have to fear, but now they are tempting to their own race.  A wicked old crab goes out for a stroll.  The walk gives him an appetite; he looks around for something to eat and spies a younger brother just moving.  Treacherously be plants himself behind a stone or shell, and watches the process, chuckling in his inmost stomach over the dainty meal in prospect.  The youthful one has just got clear of his old home and its restraints, and is delighting in his freedom, when up walks the vampire, strikes him a blow on his defenceless head, knocks the life out of him, and then sits down to a dinner of soft-shell crab.  He is an old sportsman, and enjoys exceedingly the meal gained by his own prowess.