Nursing.—This may appropriately be considered in connection with the emotions, as it seems to imply something akin to maternal affection. The eggs will not develop into larvæ unless nursed, and the nursing is effected by licking the surface of the eggs, which under the influence of this process increase in size, or grow. In about a fortnight—during which time the workers carry the eggs from higher to lower levels of the nest, and vice versa, according to the circumstances of heat, moisture, etc.—the larvæ are hatched out, and require no less careful nursing than the eggs. The workers feed them by placing mouths together—the larvæ stretching out their heads to receive the nourishment after the manner of young birds. When fully grown the larvæ spin cocoons, and are then pupæ, or the "ants' eggs" of the pheasant-rearers. These require no food, but still need incessant attention with reference to warmth, moisture, and cleanliness. When the time arrives for their emergence as perfect insects, the workers assist them to get out of their larval cases by biting through the walls of the latter. When it emerges, the newly-born ant is inclosed in a thin membrane like a shirt, which has to be pulled off. "When we see," says Büchner, "how neatly and gently this is done, and how the young creature is then washed, brushed, and fed, we are involuntarily reminded of the nursing of human babies." The young ants are then educated. They are led about the nest and taught their various domestic duties. Later on they learn to distinguish between friends and foes; and when an ant's nest is attacked by foreign ants the young ones never join in the fight, but confine themselves to removing the pupæ. That the knowledge of hereditary enemies is not wholly instinctive is proved by the experiment of Forel, who put young uneducated ants of three different species into a glass case with pupæ of six other species—all the nine species being naturally hostile to one another. Yet the young ants did not quarrel, but worked together to tend the pupæ. When the latter hatched out, an artificial colony was formed of a number of naturally hostile species, all living together like the "happy families" of the showmen.
Keeping Aphides.—It is well and generally known that various species of ants keep aphides, as men keep milch-cows, to supply a nutritious secretion. Huber first observed this fact, and noticed that the ants collected the eggs of the aphides, and treated them with as much apparent care as they treated their own. When these eggs hatch out, the aphides are usually kept and fed by the ants. Sometimes the stems and branches on which they live are incased by the ants in clay walls, in which doors are left large enough to admit the ants, but too small to allow the aphides to escape. The latter are therefore imprisoned in regular stables. The sweet secretion is yielded to the ants by a process of "milking," which consists in the ants stroking the aphides with their antennæ.
Sir John Lubbock has made an interesting addition to our knowl-
