_The Paper Nautilus_, or argonaut, secretes a thin, unchambered shell in which its eggs are carried; has tentacles or arms with which it crawls on the bottom, and swims backward, usually with the back down, squirting water through its breathing funnel. The argonaut differs from the true nautilus in having larger arms of more complicated structure, with sucker discs, and partially connected by a membrane at the base. It has an ink gland and sac, for its secretion. It has a great number of little cells, containing pigment matter of different colors, whose contractions and expansions give it a remarkable power of rapidly changing its tints. There is no internal shell, and it is ascertained that the external shell is peculiar to the female, and is only an incubating and protective nest for the eggs. The eggs are attached to the involuted spire of the shell, behind and beneath the body of the female. From the fact that the animal has no muscular or other attachment to its shell, and has been known, after quitting it, to survive sometime without attempting to return, the argonaut has been supposed to be a parasitic occupant of the cast off shell of another, but is now pretty clearly proved to be the architect of its own shell, which it also repairs when broken by the agency of its palmated arms. It is said the argonaut rises to the surface, with the shell upward, turning it downward when it floats on the water; by drawing the six arms within the shell and placing the palmated ones on the outside, it can quickly sink. This explains why the animal is so seldom taken with the shell. The shell is flexible when in water, but very fragile when dry. The largest known specimen is in the collection of the Boston Society of Natural History; it is 10 by 6½ inches. For a full account of this animal see “Proceedings of the Boston Society of Natural History,” vol. v, pp. 369-381. _End of Required Reading for April._ JERRY McAULEY AND HIS WORK. BY COLEMAN E. BISHOP. Extremes of life meet in a great city. “Man, the pendulum betwixt a smile and tear,” here swings between the utmost extremes of squalor and splendor, misery and enjoyment, sin and virtue. That conflict between good and evil—old as the human soul, its arena—is waged nowhere as fiercely as here, where life is intense and assailable souls are legion. You have to go but a little below the surface of city life to find a worse than Dante’s “Inferno;” and if that were the whole story, if there were no compensating charities, one would feel it a mercy to call down on the city the desolation, and the peace of Sodom.