that in spring it was hard to find a survivor, even in the barns and houses. The fact that species tend to increase in a geometrical ratio makes these great and sudden changes frequent in many regions of the earth; but it is not often they present themselves so vividly as in the foregoing instance, for here, scene after scene in one of Nature's silent passionless tragedies opens before us, countless myriads of highly organized beings rising into existence only to perish almost immediately, scarcely a hard-pressed remnant remaining after the great reaction to continue the species.

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CHAPTER IV.

SOME CURIOUS ANIMAL WEAPONS.

STRICTLY speaking, the only weapons of vertebrates are teeth, claws, horns, and spurs. Horns belong only to the ruminants, and the spur is a rare weapon. There are also many animals in which teeth and claws are not suited to inflict injury, or in which the proper instincts and courage to use and develop them are wanted; and these would seem, to be in a very defenceless condition. Defenceless they are in one sense, but as a fact they are no worse off than the well-armed species, having either a protective colouring or a greater swiftness or cunning to assist them in escaping from their enemies. And there are also many of these practically toothless and clawless species which have yet been provided with other organs and means of offence and defence out of Nature's curious armoury, and concerning a few of these species I propose to speak in this place.

Probably such distinctive weapons as horns, spurs, tusks and spines would be much more common in nature if the conditions of life always remained the same. But these things are long in fashioning; meanwhile, conditions are changing; climate, soil, vegetation vary; foes and rivals

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70 The Naturalist in La Plata.

diminish or increase; the old go, and others with different weapons and a new strategy take their place; and just as a skilful man "fighting the wilderness" fashions a plough from a hunting-knife, turns his implements into weapons of war, and for everything he possesses discovers a use never contemplated by its maker, so does Nature --only with an ingenuity exceeding that of man--use the means she has to meet all contingencies, and enable her creatures, seemingly so ill-provided, to maintain their fight for life. Natural selection, like an angry man, can make a weapon of anything; and, using the word in this wide sense, the mucous secretions the huanaco discharges into the face of an adversary, and the pestilential drops "distilled" by the skunk, are weapons, and may be as effectual in defensive warfare as spines, fangs and tushes.

I do not know of a more striking instance in the animal kingdom of adaptation of structure to habit than is afforded by the hairy armadillo--Dasypus villosus. He appears to us, roughly speaking, to resemble an ant-eater saddled with a dish cover; yet this creature, with the cunning Avhich Nature has given it to supplement all deficiencies, has discovered in its bony encumbrance a highly efficient weapon of offence. Most other edentates are diurnal and almost exclusively insectivorous, some feeding only on ants; they have unchangeable habits, very limited intelligence, and vanish before civilization. The hairy armadillo alone has struck out a line for itself. Like its fast disappearing congeners, it is an insect-eater still,

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Some curious Annual Weapons. 71

but does not like them seek its food on the surface and in the ant-hill only; all kinds of insects are preyed on, and by means of its keen scent it discovers worms and larvae several inches beneath the surface. Its method of taking worms and grubs resembles that of probing birds, for it throws up no earth, but forces its sharp snout and wedge-shaped head down to the required depth; and probably while working it moves round in a circle, for the hole is conical, though the head of the animal is flat. Where it has found a rich hunting-ground, the earth is seen pitted with hundreds of these neat symmetrical bores. It is also an enemy to ground-nesting birds, being fond of eggs and fledglings; and when unable to capture prey it will feed on carrion as readily as a wild dog or vulture, returning night after night to the carcase of a horse or cow as long as the flesh lasts. Failing animal food, it subsists on vegetable diet; and I have frequently found their stomachs stuffed with clover, and, stranger still, with the large, hard grains of the maize, swallowed entire.

It is not, therefore, strange that at all seasons, and even when other animals are starving, the hairy armadillo is always fat and vigorous. In the desert it is diurnal; but where man appears it becomes more and more nocturnal, and in populous districts does not go abroad until long after dark. Yet when a district becomes thickly settled it increases in numbers; so readily does it adapt itself to new conditions. It is not to be wondered at that the gauchos, keen observers of nature as they are, should make this species the hero of many of

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72 The Naturalist in La Plata.

their fables of the "Uncle Remus" type, representing it as a versatile creature, exceedingly fertile in expedients, and duping its sworn friend the fox in various ways, just as "Brer Rabbit" serves the fox in the North American fables.

The hairy armadillo will, doubtless, long survive all the other armadillos, and on this account alone it will have an ever-increasing interest for the naturalist. I have elsewhere described how it

Armadillo killing Snake.

captures mice; when preying on snakes it proceeds in another manner. A friend of mine, a careful observer, who was engaged in cattle-breeding amongst the stony sierras near Cape Corrientes, described to me an encounter he witnessed between an armadillo and a poisonous snake. While seated on the hillside one day he observed a snake, about twenty inches in length, lying coiled up on a stoue five or six yards beneath him. By-and-by, a hairy

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Some curious Animal Weapons. 73

armadillo appeared trotting directly towards it. Apparently the snake perceived and feared its approach, for it quickly uncoiled itself and began gliding away. Instantly the armadillo rushed on to it, and, squatting close down, began swaying its body backward and forward with a regular sawing motion, thus lacerating its victim with the sharp, deep-cut edges of its bony covering. The snake struggled to free itself, biting savagely at its aggressor, for its head and neck were disengaged. Its bites made no impression, and very soon it dropped its head, and when its enemy drew off, it was dead and very much mangled. The armadillo at once began its meal, taking the tail in its mouth and slowly progressing towards the head; but when about a third of the snake still remained it seemed satisfied, and, leaving that portion, trotted away.

Altogether, in its rapacious and varied habits this armadillo appears to have some points of resemblance with the hedgehog; and possibly, like the little European mammal it resembles, it is not harmed by the bite of venomous snakes.

I once had a cat that killed every snake it found, purely for sport, since it never ate them. It would jump nimbly round and across its victim, occasionally dealing it a blow with its cruel claws. The enemies of the snake are legion. Burrowing owls feed largely on them; so do herons and storks, killing them with a blow of their javelin beaks, and swallowing them entire. The sulphur tyrant-bird picks up the young snake by the tail, and, flying to a branch or stone, uses it like a flail till its life is battered out. The bird is highly com-

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