strikingly characteristic of the Megachilidæ, was evidence of the most positive kind that Pelopæus had nothing whatever to do with their putting together. It bespoke a piece of work that was entirely beyond the highest capability of her being to execute.

Each of the included leafy cells was one and one-eighth inches in length, and just barely exceeding one-fourth in width. Elliptical pieces of Spiræa, less in size than those previously described, but arranged in a similar manner, composed the several structures. Within each, a dead but perfectly-formed Megachile, encased in a cylindrical bag of silk, was found, so that there could be no possible doubt of the builder. That this inner fabric was the labor of some mother Megachile admits not of a scruple, for no other bee is known to construct a nest of like character. But what of the outer enveloping fabric of mud? It was clearly impossible for the skill of a Megachile, who, while certainly fitted for tunnelling the ground and for snipping circular and elliptical pieces of suited dimensions from leaves with all a tailor's precision, would find herself wofully unadapted for the making of mortar and the building of nests, in imitations of tunnels, out of pellets of mud that had to be moulded into consistency and shape by the jaws of the builder. Pelopæus alone, of all hymenopters, possesses the ability and means of making such structures. Megachile, who is known to occasionally build under the boards of the roof of a piazza, might sometimes in her quest of a place appropriate the discarded cells of some pre-existent Pelopæus for nesting purposes, but she runs a very great risk in so doing, for the Mud-dauber does not always build a fresh home for her treasures, save when there is a lack of the last year's structures. Old nests, when found, are put in speedy repair and made to do as invaluable a service.

BATTLE BETWEEN ANTS.

WHILST reclining one beautiful May afternoon in the shade of an oak that stood on the outskirts of a thicket, my attention was arrested by the activity and bustle presented by a colony of yellow ants, which proved to be the Formica flava, so common everywhere.

Scattered indiscriminately about were numberless larvæ in various stages of growth, and not a few immobile pupa, that had been brought up from subterranean domiciles by thoughtful nurses, while here and there were a dozen or more ants, but recently escaped from their mummy-cases, basking in the sun's warmth, preparatory to entering upon the duties of the formicarium.

The very picture of restlessness and anxiety were these full-grown neuters. That something was transpiring, or was about to transpire, seemed not unlikely, for ovæ, larvæ and pupa were being quickly carried to places of concealment in the earth, or hustled away among the entangling and interlacing grasses.

Looking about for the cause of all this excitement, the truth at once became painfully apparent. Three large, burly ants, representatives of Formica subterranea, a black species that is everywhere abundant in wooded regions, had intruded their obnoxious presence into the happy colony, bent, as it was evident, on pillage or slaughter.

Were plunder the inspiring motive, these giant invaders were not slow to learn that their weaker kin, though lacking their strength, could more than match them in cunning and stratagem.

Not daring to attack the foe, and being unwilling that any of their number should be led into slavery, or suffer aught at the hands of others, they immediately set to work to destroy all whom it was impossible to protect.

Detailed as most of the neuters seemed to be in looking after the wants of the immature, there were a few observed running hither and thither and seizing in their jaws the newlydeveloped, not to bear them out of the reach of danger,

as was at first supposed, but to kill them so as to prevent them from falling a living prey into the hands of the enemy.

Knowing the sympathy and affection which the nurses are ever wont to cherish towards the objects of their care, this act of cruelty struck me as something very astonishing and peculiar.

Prompted by curiosity to know the nature of the wounds thus inflicted, I placed upon the palm of my hand one of the wounded ants, and made, by means of a microscope, a

careful examination of its injuries. Above and below the abdomen, between the second and third segments, two deep wounds, which met each other in the interior, were plainly to be seen.

Several cases of the kind were afterwards noticed. These were not accidental occurrences, made through efforts to carry the young to places of shelter. Possibly, through inexperience, accidents might happen once in a long time, but to suppose that insects, accustomed to handling their young as the neuters assuredly are, would be likely to make such blunders, is too unreasonable to be entertained. Admitting for argument's sake that such things might occasionally occur, would successive repetitions be expected? I apprehend not. But on the supposition that a purpose was thereby subserved, the object had in view warrants, it would seem, the means employed for its accomplishment.

What the purpose was it will now be my aim to show. That many animals, tame as well as wild, are wont to destroy disabled and wounded companions, is well established by history. In many instances the destruction is justified to preserve the herd or pack from the close pursuit of enemies. "Instinct or reason," as Darwin says, "may suggest the expelling an injured companion, lest beasts of prey, including man, should be tempted to follow the troop."

Audubon, in writing of the wild turkey, so abundant in his day, observes substantially that the old males in their marches often destroy the young by picking the head, but do not venture to disturb the full-grown and vigorous. The feeble and immature being an encumbrance, it is obvious that the watchfulness and attention which they would require, were sympathy and affection the emotions by which the males are actuated, would necessarily retard progress, and lead to the destruction of the entire flock. Instinct or reason here operates for individual and family good.

Granting that instinct or reason does sometimes act for individual and family preservation in the manner described,

I am not willing to admit that in every case that may arise in which the weak and disabled are sacrificed, that it is done for the material benefit of the physically able and robust. How the destruction of the weak and nearly-developed ant can result in good to the colony, in view of the fact that not the slightest effort to escape the danger by flight is undertaken, the sole object being the hiding of the young, it is most difficult to conceive.

There seems to be one of two theories, in the writer's judgment, that will, in anything like a satisfactory manner, account for this strange, abnormal habit upon the part of an insect that has been proverbially distinguished for its kind and affectionate disposition towards the tender beings committed to its trust; either to attribute it to an unwillingness and dislike to see its offspring made the servants of a hostile race or the subjects of ill-treatment and abuse, or to the survival of a habit of the past when its ancestors were a migratory, or nomadic, species.

That a feeling of repugnance does sometimes take possession of animal nature when the objects of parental care and solicitude are, or are about to be, reduced to slavery or confinement, and impels to actions of cruelty, will be patent from what follows:

A friend, several summers ago, having procured a pair of young robins, placed them in a cage, which he hung from a tree-branch close to his dwelling, where the parent-birds could have an opportunity to feed them. All went well for a few days, when the parents, who had busied themselves in the intervals of feeding in attempts to secure their release, finding their efforts unavailing, flew away, but only to return with something green in their bills, most probably poisonous caterpillars, which they fed to their offspring. A few minutes later and they lay in the bottom of the cage dead, but the parents, as if conscious of what would result, flew away, and never came back.