Part 19

It has been established that several species of fish in the lagoon make distinctive sounds. One, a large black fish with a yellow belly and four whiskers on each side of its face, expresses sounds like a baby’s fretful crying. A large chocolate-colored fish found among the bottom rocks makes a sound “like the distant echo of a large firecracker.” There is a curious little scaleless fish found in schools of 100 or more; as the school moves through the water it produces a chorus of tinkling sounds. A phosphorescent light comes from inside the throats of these animals. Among all his catches Fr. Lange has found nothing which can be identified with the singing fish, but he is convinced the music comes from a living organism.

That fish can and do make sounds now is well-known. This was demonstrated conclusively by U. S. Navy investigators during the late war. They determined the characteristic sounds made by a large variety of sea creatures whose chatter was interfering with underwater sonic devices.

_Brazil’s Vicious Glow Worm_

One of the most unusual of all luminous creatures is an insect larva found by farmers ploughing damp soil in Brazil and Uruguay. It is a reddish-brown little worm with rows of green lights on both sides and a vivid red lamp on the front of its head. The red light is actually red—not white light shining through a reddish skin. Adult females of the species retain the same luminous pattern. Male adults have only feeble, yellow lights. The larva are extremely vicious little creatures, predators on white grubs which infest the soil.

_Grasshoppers Like Chameleons_

There is a jet-black grasshopper that turns sky-blue at sunrise. The curious creature is found on the summit of Mount Kosciusco, highest peak in Australia, where snow lingers into late summer and nights are bitter cold.

The insect is of peculiar interest because of a temperature control mechanism otherwise unknown in nature. Several animals, notably chameleons and some fish, can change color, usually to match their environment. The changes are brought about by certain hormones, released by stimulation of the eyes, which activate different color cells in the skin. But in this grasshopper every one of the outer layer of cells of the body is a color cell. On the surface are granules of black pigment, underneath granules of blue. These change places in response to temperature changes. At approximately 25 degrees C. the blue granules rise to the top, displacing the black. At 15 C. the reverse happens. This displacement can be brought about only by temperature change. Australian entomologists have in vain tried every other sort of stimulus, including illumination with various wave lengths of light.

The phenomenon probably is protective. Seemingly because it is very cold at night on the high mountaintop the black pigment absorbs and retains all the heat available. It is as if the grasshopper carried a woolen blanket. With sunrise an abrupt change takes place; and the days often become intensely hot. If the black coat were retained, the grasshopper would become overheated and probably die. The blue reflects much of the heat.

With the first streaks of sunlight grasshoppers which have slept all night at the foot of grass stalks begin creeping slowly upward. There apparently is no nervous control of the color change. Each color cell seems to act independently. The same reaction takes place in dead grasshoppers when the temperature changes, affecting even fragments of their bodies. It is possible to get a grasshopper half black and half blue by heating one end and cooling the other.

_Beetles That Helped an Army_

During the invasion of Normandy in 1944 Army jeep drivers prohibited from using headlights of any sort, were able to follow winding country roads on the blackest nights by rows of millions of flashing green lights which outlined the roadsides.

Wingless, wormlike female beetles, (Lampyris hoctiluca, the European glow worm) were trying to attract their winged, lightless mates. Their nocturnal lovemaking as they clung to roadside weeds and bushes was a far from insignificant factor in the Normandy operations. The worms indicated not only the direction but the width of the roads, thus forestalling fatal accidents and preventing drivers from going astray into hostile territory. However, they doubtless proved of equal value to the enemy. These accommodating creatures, unknown to soldiers from across the Atlantic, should not be confused with our familiar fireflies.

_Worms in Medical History_

Earthworms have an important place in folk medicine, especially in the Near East. Muzhatu-L-qylut of Hamd Allah, an ancient Persian natural history, states: “Earthworms are red worms living in the damp earth. Baked and eaten with bread they reduce the size of stones in the bladder. When dried and eaten they cure the yellowness of jaundice. In difficult labor they bring on delivery immediately. Their ashes applied to the head with oil of roses make the hair to grow.”

Says a seventeenth century English medical treatise: “Earthworms are hot of nature and of them are a pressious oyntment made to close woundes; and if they be sodden in goose greece and styned it is a good oyntment for to drop into a dull hearing ear. Earthworms stamped are good for payned teeth. The oyle of earthworms be greatly commended for comforting of sinews, jointes, vaines and goute. They must be washed in white wine and the oyles of verbascum or cowslopes, of roses, of lilies, of dil, of chamomill, all sodden together. When it is cold put in your erthwormes, stoppe your glass, let it stand xl days in the sunne, then straine it. It will make an excellent oyle against ache, sciatica, goute, etc.”

_Toads That Make Poison Gas_

Among the weirdest of American amphibians are certain of the giant toads of southwestern United States and northern Mexico which, when frightened or in pain, diffuse a deadly gas which will kill objects some distance away.

A very large toad found almost everywhere throughout the Panama Canal Zone can squirt a poison which may permanently blind a man if it hits the eyes. Nobody would bother it except that from its skin is made of the softest and most expensive of all leather.

Most toads have skin covered with warts which are more closely grouped on the sides of the neck than elsewhere. These, together with the paratoid glands situated behind the eyes, secrete a milky, poisonous fluid whenever the animal is molested. The secretion is an acid irritant, causing pain in cuts and producing a bitter, astringent sensation in the mouth.

_Plants That Thrive on Ice-Bloom_

There are plants that grow in ice and snow. This phenomenon—known to botanists as cryovegetation—has been the subject of intensive study at Mt. McKinley National Park in Alaska.

The plants are responsible for the strange phenomenon of ice-bloom. Ice fields at various seasons take strange colors. The plants are very minute members of the almost universal algae family which are among the most primitive forms of life on earth. They are able to extract the nourishment they require from the surface of a glacier as it melts slightly under the glare of the Arctic sun. The phenomenon has been reported by Arctic explorers for many years but until a few years ago very little was known of the responsible microorganisms. They are a striking demonstration of the fact that life has spread to all possible habitats on earth in some form or other, even to fields of solid ice.

While nobody is likely to stake out a few thousand acres of glacier for a farm, an Hungarian botanist, Dr. Ersebet Kol, has made first-hand studies of the conditions under which the minute plant organism could live and multiply, including the acidity of the ice. Concerning the Columbia glacier, one of the largest in the Alaska ice-fields, Dr. Kol reported to the Smithsonian Institution: “When I stepped on the ice, I saw for the first time a phenomenon to be seen only on coastal glaciers. The surface of the ice was covered for miles and miles with light brownish-purple algal vegetation called ice-bloom. This effect is produced by immense quantities of minute plants called Ancyclonema, a characteristic plant of the permanent ice. It can never be found elsewhere, even on permanent snow. It belongs to the green algae first found on the coast glaciers of Greenland. Since that time, the microorganism has been found in several localities in Europe, and I have found it occasionally on the glaciers of the interior but never in sufficient quantities to form the ice-bloom of the coastal glaciers.

“Here I had an opportunity of studying another striking phenomenon of the permanent snow regions of Alaska—colored snow, especially red snow. Above Valdez, around the Thompson Pass, the snowfields glitter with a reddish color in the beginning of August. The snow was red not only on the surface, but also to a depth of several inches and even in one place to a depth of two feet, caused by the presence of millions of tiny plants, Chlamydomonas nivalis. The snow on Thompson Pass looks as though it has been sprinkled with red pepper, differing in this respect from the red of other snowfields, which is usually a light raspberry red.”

_Poison Arrow Frogs_

There is a green frog, about the size of a half dollar, that is one of the most virulently poisonous creatures on earth—but only after it has been roasted alive. It is common at the Smithsonian Institution’s tropical wild life preserve in the Panama Canal Zone. When living it is quite harmless, at least to human beings although some believe it can poison other frogs. When it is roasted over a slow fire, however, a toxin is exuded from its skin which is a potent nerve and respiratory poison. It once was used by the Choco Indians to poison the arrows with which they hunted game and Spaniards.

The poison arrow frog is a delicate creature which is confined to a narrow temperature range and probably never has reached the United States alive. A ground and tree-dwelling animal, it is quite elusive.

A close relative is a brilliant scarlet frog, a denizen of the treetop of the dense Panama rain forest. From its skin also is exuded a virulent poison. One of the two jungle canopy frogs, it is less than an inch long. Its body has deep scarlet both above and below; its feet are black and its thighs are flecked with metallic green on the rear and metallic blue on the front. It is found only on the Atlantic side of the isthmus near the mouth of a small bay where Columbus once landed for fresh water. Outside its narrow range the creature has never been seen in its gorgeous colors. In captivity it probably would die very quickly. Placed in a preservative, it quickly turns to a drab, uniform black.

The animal is a remarkable and peculiar climber. It ascends a tree trunk by a series of short jumps, catching its toes in rough spots on the bark. (Other tree frogs have suction disks on their feet by means of which they can walk up a tree in leisurely fashion.) It makes its way unerringly from the ground to its treetop home, a pool of water in the axil of a bromilead or “tank plant,” a tree of the pineapple family.

_The Seal That Can “Lose” Its Head_

An animal that can pull its head almost completely into its neck has recently been added to the mammal collections of the Smithsonian Institution. This is the Ross seal, one of the rarest of all the seal family in the Antarctic.

A frozen specimen captured by the Navy’s polar expedition in 1956 arrived at the U. S. National Museum in Washington in excellent condition. This seal—about 8 feet long—dwells exclusively on the drifting ice pack of the Ross Sea. So far as is known it never comes on land or on the ice shelf. It apparently feeds almost exclusively on cuttlefish and squid, which are abundant in Antarctic waters. To judge by the nature of its teeth it undoubtedly is not a fish-eater. It is yellowish-green on the underside and blackish-brown on the top, the fur often being marked with pale streaks along the sides.

On the drifting pack it has fearsome enemies—notably the killer whale and the writhing, snake-like sea-leopard, most savage of the seal family—which may account for its relative scarcity. The outstanding peculiarity of the creature, probably unique among mammals, is the thick bloated neck into which the head can be withdrawn. This may be a protective characteristic although it could hardly serve the creature against its fierce enemies. On the other hand, withdrawal of the head may be a comfortable habit in a very cold climate.

_The Delectable Horned Viper_

All along the Nile and the Red Sea coast is found the horned viper which lives buried wormlike in the sand with only its eyes and the upper part of its head visible. Its horns are said to look like barley grains and to entice birds. It is found often in rodent holes. This horned viper is extremely tenacious of life. It has been kept alive in a glass jar, without food, for two years. It can hurl itself forward as much as three feet. A full-grown specimen is about 18 inches long and quite poisonous but Egyptian magicians have been seen eating the animals like stalks of celery.

_Flying Snakes, Frogs and Toads_

There are flying snakes as well as flying frogs and toads. Such reptiles and amphibians should be considered expert parachutists rather than actual flyers.

The tree snakes dendrolaphis and chrysopelea leap from high limbs, stretched out lengthwise and both flatten and broaden the body so that it presents a concave surface. They glide to earth slowly, at an angle to the vertical, and land apparently without injury.

Frogs of some species have enormous webs between the fingers and toes which serve as parachutes. A Brazilian tree frog has been observed to drop from an altitude of 100 feet and land 90 feet away uninjured. Since other frogs of the same size were killed when dropped vertically, parachuting must be considered a distinct trait of this particular species, developed over many generations of life in treetops.

In the course of experiments a South Carolina lizard, frequenter of bushes and fences, landed ten to twelve feet away from the place where it was dropped, at a height of 37 feet, and hopped away unhurt. It took a rigid posture when dropped, limbs outstretched and stomach taut. It fell vertically a third of the distance to the ground and then started to glide. A lizard of another species from the same habit wriggled all the way down.

_Eagles Build Log Cabin Nests_

The white-headed eagle became the national bird of the United States by act of Congress on June 20, 1782. For nearly two centuries it has remained the American symbol of fearlessness and freedom. The same bird—Haleoletus leucocephalus and not the more familiar golden eagle found in the West—had been the supreme totem animal of the Six Nations of the Iroquois from whom many institutions of the new republic indirectly may have been derived.

This eagle still is fairly abundant in the fringes of forest around the Great Lakes, its fishing grounds. Its nest, almost always at the top of a tall sycamore or hickory which is dead or dying, is almost literally a log cabin. The bird sometimes uses sticks six feet long for the outer walls. It grasps large dead branches in its talons, breaks them off by sheer force, and flies away with them. A recently observed nest was nine feet high and six feet in diameter.

_The Predatory Mantid_

Why does the “praying mantid” pray? The prayerlike pose of this near relative of the cockroach is its normal position both for seizing its victims and for defending itself.

For their size mantids are among the most predatory animals in existence. They are also among the least known of the insects. There are more than 1500 species in the world, mostly tropical. Only 19 are known in the United States which is on the northern fringe of their normal habitat. One of the most remarkable features of the mantid is its front legs, which bear sharp spines and fold in a curious hinged fashion enabling the insect to reach forward, seize a fly or some other victim, and bring it to its mouth. This is the explanation for the seeming attitude of prayer.

Mantids feed entirely on other animals, chiefly insects caught alive. Instances of small birds, lizards and mice being eaten have been reported, probably due to mistaken observations. There is no question that mature individuals of several species can handle any caterpillar, grasshopper, cockroach or other large insect that comes within its range. Their appetite is enormous. An adult mantid has been known to eat ten cockroaches in less than three hours. Bees and wasps usually have no terrors for the predators, although occasionally a mantid is stung while trying to catch a wasp and gives evidence of the injury.

Sometimes the mantid’s front legs are held in a posture of sparring, rather than of prayer. More than once the sight of one of these insects “sparring” with an English sparrow or some other small animal has attracted a crowd on a city street and gotten paragraphs in the local newspapers.

The mantid usually waits motionless until its prey comes within reach but sometimes, supposedly when very hungry, it may stalk another insect. Sometimes the victim is touched lightly with the antennae before the front legs flash forward and make the capture.

These insects have developed considerable camouflage. Some tropical species look like flowers, their colors blending with those of foliage. One species varies in color from white to pale pink and has the practise of crouching among certain blossoms, the petals of which its legs and other body parts resemble. Others have arranged themselves on plants so that they look like blue flowers. Presumably bees and other flower-loving insects thus are lured to their doom. A few tropical mantids have developed a superficial resemblance to other insects of the same environment which are distasteful to birds and monkeys. Some closely resemble large ants.

There is a widespread belief that the male always is eaten by the female after mating. Sometimes this happens, but the male never is a willing victim and quite frequently escapes. The eggs are laid in groups of from a dozen to about 400. They are deposited in layers in the midst of a thick frothy liquid which soon hardens and becomes fibrous. For the most part, each species deposits egg masses of a distinctive shape.

On the whole, they probably are beneficial insects because the greater part of their prey consists of species injurious to gardens. The possibility of propagating them for the control of injurious insects, such as Japanese beetles, has been suggested because of their notoriously big appetites. It would, however, be impossible to restrict them to a specific pest. They would continue to eat about every living creature of the right size that came within reach of their claws, including many beneficial species.

_Fireflies as Electricians_

The flashing of a field of fireflies is an expensive show. For two generations one of the ideals of science has been to produce artificially “cold light”—radiation confined entirely to those wavelengths to which the retina of the human eye is sensitive without any energy being wasted in the form of heat or invisible light. Could the ideal be attained with the same expenditure of fuel and power as is required for light production at present the world’s bills for illumination would be decreased enormously.

Actually the firefly has attained this ideal in one direction. It emits only visible light. From this point of view the firefly or any other sort of luminescent animal is very efficient indeed. A good part of the total radiation from any man-made source of light—or for that matter from the sun—is invisible infrared, observable only as heat. Possibly the firefly produces some heat in its light production but it is too little to be measured. It is safe to say that within a tiny fraction, 100% of the radiation produced is in the visible spectrum—most of it shorter wave lengths than those which produce the sensation of blue light. This is by far the highest efficiency known to science.

Chemists can duplicate the process to a certain extent. Consequently a great deal of research has been devoted to the light-emitting mechanism, physical and chemical, of the insects. Firefly luminescence is due to the oxidation—that is, the burning—of a chemical substance, luciferin. This reaction, in turn, depends upon a catalyst known as luciferase. The same phenomenon can be brought out by appropriate mixtures of luciferin, luciferase, and oxygen in a test-tube at the proper temperature.

All these experiments have shown that, considering the amount of oxygen necessary, it is a very wasteful process. It is far less efficient than most means of producing artificial light known to man—one percent compared with the 4.54 percent of the carbon filament; 17.17 percent of the acetylene flame, or 60 percent of the sodium arc light. To illuminate houses or streets with firefly light would be a very expensive procedure indeed.

Dr. N. D. Maluf of Yale University quotes a calculation that “an area of firefly light six feet in diameter on the ceiling of a room nine feet high would give ample illumination for reading or drawing on a table three feet high.” This would hardly interest an illuminating engineer. The light can, however, be used in an emergency. During the Spanish-American War Major General W. C. Gorgas is reputed to have used the light from a bottle of fireflies to perform an emergency operation. The average householder would rebel at the monthly bills.

The actual light from a single firefly is very minute indeed, averaging little more than 25 thousandths of a candle power. The combined courtship efforts of a whole field full of the insects would hardly light a single room enough for sewing or reading. The insect will sometimes glow steadily with a light as low as two hundred-thousandths of candle power intensity.

Among fireflies, flashing is essentially a courtship phenomenon, yet there is no discernible difference between the quality of the light of male and female insects. What actually happens is that the flash of the female in response to the signal of the male is timed almost exactly at a trifle over two seconds. The male is instinctively aware of this time interval, so that he does not become confused with the signals of other males. In a large group of the insects the flashes of the two sexes tend to become synchronized, producing a field of light.

_The Mollusk Vampire of Hell_

Black demon of the realm of everlasting dark is Vampyrotouthis infernalis. Most nightmarish of living animals, this “vampire of hell” has a midnight-black body about two inches long, red-brown round face on a head almost as large as the rest of the body, red eyes an inch in diameter encircled by narrow bands of pinkish-orange, rows of ivory white teeth, ten wriggling, ever-probing tentacles extending from the head. On the sides of the neck are two powerful, flashing lights each of which is a cluster of about 50 tiny phosphorescent nodules. The entire body is covered with hundreds of tiny lights.