arranging the whole to his mind, and again and again adjusting it until he was satisfied; after which he hung or hovered over the surface of the nest, his head close to the orifice, the body inclined upward at an angle of about 45°, fanning it with the pectoral fins, aided by a side motion of the tail. This curious manœuvre was apparently for the purpose of ventilating the spawn; at least by this means a current of water was made to set in toward the nest, as was evident by the agitation of particles of matter attached to it. This fanning, or ventilation, was frequently repeated every day till the young were hatched; and sometimes the little fellow would dive head foremost into his nursery and bring out a mouthful of sand, which he would carry to some distance and discharge with a puff. At the end of a month the young ones were first perceived. The nest was built on the 28d of April; the young appeared on the 21st of May."
After the young are actually hatched, the fond parent only redoubles his delicate attentions. He never leaves the precincts of home by day or night; and he guards the nest with the utmost pertinacity, allowing no stray intruder from any side to approach it. If a greedy water-beetle or other enemy comes near the young, this exemplary father runs full tilt at him with his armed spines, pounces upon him broadside, and unceremoniously shoves or tumbles him over. If you try to disturb him in an aquarium with a stick or pencil, he will charge at it smartly, and strike it so hard that the blow can be distinctly felt by the hand that holds it. Among the enemies he has to repel on such occasions, I regret to say (for the honor of maternity I would fain conceal the fact), are the mothers themselves of his little charges, who wish to emulate Saturn and the common rabbit by making a dinner off their own flesh and blood. "For a whole month," says Dr. Gunther, "he watches over his treasure, defending it stoutly against all invaders, and especially against his own wives, who have a great desire to get at the eggs." Those unnatural parents, indeed, make such a dead set upon their young and the devoted father who guards them, that, as Mr. Darwin cynically observes, "it would be no small relief to him if after depositing their eggs they were immediately devoured by some enemy, for he is forced incessantly to drive them from the nest." Let us trust that the wedded stickleback himself never indulges in such uxoricidal fancies.
The fry, when hatched, are at first so very minute and transparent that you can with difficulty perceive them in the water of an aquarium, and even so only by the gentle fluttering motion of their wee fins. Their good papa continues, however, to perform the duties of a nurse for them with profound vigilance, confining them at first to the meshes of the nest, and, when they stray too far, gently leading them back with unremitting kindness to the path of duty. By degrees, as their knowledge of the world increases, he wisely allows them to indulge in greater excursions, and hollows out for them a small basin in the sand
