The popularity of tropical fishes is due to various reasons. For one thing you will have a constant source of delight in their gorgeous coloring, which includes all the colors of the rainbow mixed together in profusion. Again, the remoteness of their origins adds a romantic interest to these beautiful little fish. Nor is it difficult to keep them, for they adapt themselves beautifully to home aquaria (an aquarium is a tank for marine animals; the plural is aquaria).

Tropical fishes may be divided into two groups, the live-bearers, which as the name implies bear their young alive, and the egg- layers, which reproduce through eggs. The first kind, the live-bearers, may be found in great numbers and many varieties in our own hemisphere. The other group of fish, the egg- layers, includes many more varieties and these are found in many parts of the world.

Tropical fish have been bred in such large numbers in this country that the number imported has been continually decreasing. Generally speaking, only the rarer species are now imported.
While almost all the small tropical fishes can be kept in home aquaria, there are some important rules that must be observed if the fish are to be kept in good condition.

For one thing, since fish have a soft mucous coat over their scales to protect them against bacteria, the water must be soft or this mucous coat will be destroyed with consequent harm to the fish. If the tap water is too hard, rain-water or water from a pond may be used. Furthermore the water should be kept sweet by healthy plants, which liberate oxygen and absorb gases that are harmful to the fishes.

An aquarium of five, ten or fifteen gallon capacity should have enough coarse sand to cover the bottom to a depth of at least an inch. It should be placed near a window, so that the plants will have sufficient light. Better results may be obtained by using artificial light from a reflector that fits over the top of the tank. A reflector of this sort concentrates the light on the fish and plants and brings out the best coloring of both. Besides, artificial light supplies a steady, dependable source of light. An ordinary 40-watt incandescent lamp will suffice for a io-gallon tank and a 50-watt lamp for a x-gallon tank. This artificial light should operate at least eight hours a day.

An important thing to remember is that most tropical fishes are jumpers and that many of them could easily leap from the average aquarium. To keep them from doing so, place a glass cover (window glass will do) over the entire aquarium. This glass will also keep out dust and other foreign matter. Be sure that the glass cover fits loosely, so that air can easily enter the aquarium.

The plants called Vallisneria, Sagittaria Sinensis, Sagittaria Subulata, hairgrass and spatterdock may be put in the aquarium. Remember that the front center of the aquarium should be left free of plants so that you may be able to observe the fish without difficulty.

When you have put the plants into the tank, a period of three days should elapse before you introduce the fish into the aquarium. This three-day interval will give the plants a chance to grow, and the chlorine that is often present in water for purifying purposes will have disappeared. As this chlorine is harmful to fishes, they should not be placed in fresh tap water.

When the water in the tank has been well conditioned, it is time to stock the aquarium with fish. In order to have enough oxygen for the fish, not more than two fish per gallon should be put into a tank. A good collection to start with would be a pair each of Angel Fish, Red Platies, Zebras, Black Mollies and Guppies.

The Angel Fish is noted for its haughty, dignified manners. The black vertical bars across the body contrast beautifully with the underlying silver-green. The Red Platy is a beautiful fish, vividly colored. The young in some strains are gold in color but become blood red as they reach maturity. The Zebra is the most peaceful of all aquarium fishes. Though it may chase other fishes, this is due only to its habit of swimming in schools. If there are no other Zebras in the tank, it will follow the fish of different species. The Black Molly is the only fish suitable for aquarium purposes that is entirely black.

Perhaps you may want to start a colony of Guppies. This exquisite little fish is very popular with fish fanciers. Its coloring has been described as “every color combined into one harmonious whole.”

Fish do not require much food and are not very particular eaters. Any prepared food, which you may buy at your dealer’s, will answer the purpose. It is well to use two or more foods alternately and occasionally to feed a little cooked spinach to the live-bearers. Live foods, such as mosquito larv and small worms, are good; these too may be bought at your dealer’s.

Do not overfeed the fishes. The food which is not eaten lies on the bottom of the tank and decomposes, causing the water to become cloudy. Harmful gases will be formed and the water will become deficient in oxygen. Overfeeding may be avoided by feeding no more than your fish will eat in ten or fifteen minutes. If food is left after that time, you have fed too much. It would be well not to feed the next day, and to feed less thereafter. Feeding once a day is usually enough.

Snails are useful scavengers in an aquarium; they consume surplus food and decaying vegetation. The Red Ramshorn Snail is a favorite with fish fanciers. Its red shell and body make an effective contrast with the green vegetation of the aquarium. Other species of snails that are used a scavengers are the Australian Red Snail, the Pond Snail and the Trumpet Snail.

Tropical fish require a water temperature of from 70 to 8o degrees. Since variation in temperature is one of the chief sources of trouble in an aquarium, everything possible should be done to avoid or minimize this variation. It would be well to have a heater that will supply heat along the bottom of the tank. If you cannot obtain a heater for the aquarium, cover the tanks on cold nights with a blanket or other cloth covering.

In spite of all your precautions, fish may sometimes become sick. The most common fish disease is White Spots or Icli. The word Ich is really the shortened form of Ichiyophthira, a tiny parasite that causes the disease. Ich is characterized by pinched fins and white spots on the body and fins. It is best to remove the affected fish from the aquarium and to place it in a separate container. Some common salt or patent fish remedy should then be added to the water. The tiny white spots should disappear in about a week.

Another common disease is Tailrot or Fungus. The fungus is a white scummy coating that may be found on many parts of the fish. The affected fish should be placed in clean water to which some salt has been added. Swabbing the affected parts with cotton soaked in mercurochrome or vinegar is effective.

When plants and food are placed in the aquarium, fish enemies may be introduced with them: such enemies as the diving beetle larva, the larv of various dragon flies and the water scorpion. It would be well to consider all unknown bugs and larv that are found in the aquarium as fish enemies.

The tongues of some moths and butterflies are as long as their bodies. This is a wonderful adaptation of nature, enabling the insect to obtain its food.

The nectar, which is the food of these butterflies and moths, is produced in the deep, hidden pockets (nectaries) of flowers. By unrolling the tongue and thrusting it down into the far recesses of the flower, the insect is able to reach the nectar and suck it up.

This long tube has been developed in the course of ages from the jaws of the creature. Each jaw is drawn out into a long threadlike body, convex on the outer surface and concave on the inner side. Together they form a tube admirably suited for their purpose and even the nectar in the very long narrow bells of sonic flowers is within reach of the long tongue.

When at rest the tongue is coiled up spirally like the mainspring of a watch, but it is always ready and can be shot out in an instant.

The adaptation of the insect to the flower also works the other way, and in the course of ages the flower has been adapting its form to the creature with the long tongue; for, while it gives up nectar to the insect, it requires a service in return. It is by these insects that the plant is pollinated to produce seeds that will carry on the race for another generation.

In seeking the nectar the insect collects pollen from the stamens of one flower, and when it goes to another flower the pollen on its body is rubbed off on the pistil, so fertilizing it.

The secret of the camel’s unique value lies, as we all know, in the fact that these animals are so footed that they do not sink, as a hard-hoofed mammal sinks, into the sand. They walk on it as a reindeer walks on snow, upon a spreading, padded foot.

HOW THE CAMEL CAN MARCH FOR DAYS WITHOUT DRINKING

In addition to that, they can march for several days through the desert without drinking - though it is not true that a camel can support a huge burden through the wilds for two or three weeks at a time without any chance of drinking.

The camel is as fond of water as a thirsty human being, and it has no special way to store up the water. Like other animals water is stored in the tissues all over the body. A large amount of salt must be eaten to enable the camel to retain quantities of water without bad effects, but if plenty of salt is available a thirsty, shrunken camel will plump out amazingly.

It was once thought that the peculiar ‘cells” in the first two compartments of the camel’s stomach were used to store water, but the water contained in the stomach is not enough to do much good in the desert.

The hump, while not used to store water as such, is more important. It is almost all fat. When this fat is used up by the body, water is produced - as much as ten gallons in a large camel. In addition, the animal’s body draws upon that reservoir of fatty nourishment for the energy that it exhausts over its work and under privation.

THE ONE-HUMPED ARABIAN CAMEL IS WELL SUITED TO DESERT TRAVELING

There are two distinct species of domesticated camels in the Old World. One is the one-humped Arabian, covering a wide domain in northern and eastern Africa, Syria, Arabia and other parts of Asia Minor, and in northern India, Mongolia and south-central Asia. It is long-limbed with large spreading feet, soft for the desert sands. Callous pads, or cushions, upon its feet, and upon its chest, and on the joints of its legs protect these parts from being cut by the sharp grains of sand when the animal is walking, kneeling or lying down. Over its large dark eyes it has long eyelashes to protect it from the glaring sun and the whirling sands. Its nosrils, set slantwise above the split upper lip, can be closed also against drifting sand. That upper lip is very sensitive. Sight and smell are especially keen and the animal can tell at a great distance away where water is to be found. Its teeth are strong, just right for cropping the sparse plants of the esert. Its coat is shaggy, with a fringe of hair along the top of its neck and under its chin. The coat is colored like the sand. We know the shade as “camel’s hair.”

THE TWO-HUMPED CAMEL OF ASIA’S MOUNTAIN PASSES

The other species of domestic camel is the two-humped Bactrian camel of eastern Asia, similar to the Arabian but built more heavily, with longer, finer hair, which is dark-colored or fawn. Its feet are harder, for this camel lives, not in sandy deserts, but among the rocky wastes and mountain passes of northern and eastern Asia, in China, Siberia, Mongolia and India. It stands well the rigors of Arctic cold and of fierce heat.

No ‘wild species of camel has ever been found, but a two-humped variety is said to roam in Central Asia and Siberia. Even these animals may be only offspring of tame camels that escaped from man centuries ago. They may be runaways from dead civilization.

The long hair of the Bactrian camel is very valuable for making fine cloth. In spring the hair loosens and falls off in clumps. The hair is carefully gathered, cleaned and sorted. The fine undercoat makes the best cloth; the hairs are as fine as the finest Merino wool. Shawls of this material have been woven in central Asia for thousands of years; the best ones are nearly priceless. Nowadays camel’s-hair coats are its most common use.

THE DROMEDARY, A SWIFT CAMEL USED AS A RIDING STEED

You have heard the word dromedary. It is popularly taken to mean a one-humped camel. However, it has another, more special, meaning. Transportation camels are those which carry baggage and those trained for riding. The riding beasts are the dromedaries. They are chosen for their speed, and can go fifty to seventy-five or, occasionally, a hundred miles a day. The baggage camels are less fleet, but, going at fifteen to twenty- five miles a day, can carry five hundred to six hundred pounds. Camel caravans of 1000 animals or more are not unknown. The beasts proceed with a pacing motion, lifting the two left feet, then the two right feet, and so on. As you can imagine, the traveler must learn to ride, and at first it is not easy.

The camel’s bone is the finest thing nature has ever made for the frame of an animal. It is like ivory, dense and hard and splendid. In fact, camel bone is used in enormous quantities as a substitute for ivory. The shape of the blood corpuscles in the camels and their relatives, the llamas, is oval, like those of the birds and the reptiles, but unlike these, the camel’s red corpuscles have no nuclei. In all other mammals the blood corpuscles are circular.

We find another feature in the animal. Its temperature is not constant, like that of man and some other mammals. It rises with the surrounding heat, it falls with the drop of night’s fierce winds. We humans vary little more than a degree whether we are in the tropics or the Arctic; the camel’s temperature may rise and fall several degrees in the course of twenty-four hours. This is less change than in reptiles.

One would imagine that it must endure agonies in the noonday glare, for there is only one small patch behind the neck from which sweat glands pour out perspiration to relieve the heat of the animal’s body. However, when resting the camel actually prefers to kneel in the full glare of the sun rather than to seek shade. The rareness of sweat glands helps to conserve water.

The camel goes grumbling beneath its burden through a desert in heat. He always grumbles. He hates his master and everybody else; and many are the stories of camels trying to kill their drivers, and sometimes succeeding. Some camels are more morose and wicked than others, but they are never gentle or amiable. This is particularly true of the common burden-bearing camels. The swifter riding camel, the dromedary, is often better treated, and his disposition is not always so bad; but even he is not a gentle or affectionate beast.

There is not a moment of the day when a camel will not bite its master’s arm off if it has the chance. It can inflict one of the worst crunching nips possible by any pair of jaws. It will seize the hand that feeds it; it will take a piece out of a man’s back or leg; it will fasten upon a man who rides past it in a narrow mountain way and dash him down to death. It is possible that thousands of years of ill treatment have bred viciousness into it as fixedly as hardihood.

Even among themselves they fight dreadfully. Lacking horns, they use the teeth, and with these they seize a leg, and wrench and tug until they have thrown the rival, then they drop upon him with the knees, and pound him to death. A contest between two bull camels is a grim spectacle; and it is a dangerous one, for the example of the first two is infectious, and will set the other males roaring and battling among themselves with a fury not to be described, and a damage to merchandise not to be mentioned in the hearing of a native owner.

What would be rich abundance to a horse would not be acceptable to a camel. For him the lush grass of the meadow is not food; give him the prickly thorn, the scrubby thistle-like growth, and the camel paradise is there. One has seen a gaunt Arabian camel stride across a field ready for hay- making, and paddle through a brook, which camels abominate, to reach a hedge composed of forbidding briar and bramble, and feast with every sign of rapture.

The natural food of the animal is the ungenerous product of the desert. Where other animals would perish of starvation he waxes sleek and prosperous. The Bactrian luxuriates on bitter weeds and mineralized water, salt to the taste. It is marvelous to what ends such food can be turned. Had it been otherwise, had the camel required sustenance like that of deer and cow and antelope, human history would have been different.

We never could have crossed the deserts; the steppes would have been a barrier between Asia and Europe not to be passed. Solomon could not have built his temple at Jerusalem; the Phenicians could never have got their vares to the coasts; during the Middle Ages tea, spices, the silk and satin and gems of the East could never have come to Europe had not camels on poverty’s fare carried the burdens asked of them.

The camel serves in more ways than as a bearer of burdens. Milk from the females; flesh from the young and the old; ropes, tents, fine shawls and rugs and clothes from the hair—all these are derived from the animals. Hides and bones are also converted to human use. In time of war, a camel corps is more useful than horse cavalry in parts of Africa and India, and both British and French maintain camel units.

We shall need the camel for a long time. The desert parts of the world in which he is useful are not likely to have many railroads or motor roads soon, if indeed they are ever built, through some of the wastes. Airplane1;, to be sure, are being used in the East for long trips, but a camel can go where airplanes can not land. No other means of transportation seems likely to replace the camel soon.

Yet, for all his wondrous mastery of a melancholy, forbidding land, the camel is not a native of the place in which we find him. The story of his origin and wanderings matches all the romance of his latter- day career in domestication.

Though fossil camel forms suggest that the Arabian camel may have arisen in India, the camel tribes began in North America. Many types of camels were found in the \Vest, from the early beginnings until the coming of man.

THE FIRST CAMELS WERE ONLY ABOUT AS BIG AS FOXES

The first camels were about the size of a fox and had four toes on each foot, the side toes small and soon to disappear. From these long-extinct ancestors many kinds developed, some gazelle-like but others much larger than any still alive. The giraffe-camel was so called becnuse it had a long neck and long legs, like the giraffe, and these features enabled it to feed on the tops of the trees. just before men appeared on the scene, some of the camels went off into Asia while others wandered down the newly established bridge to South America. Then for some unknown reason the ones left behind in North America died out.

Fortunately those that picked their way along the untrodden mountains throve. They are there to this day. The South American llamas, alpacas and vicuñas are the only existing cousins of the camels.

First we have the wild vicufla, the smaller of two wild species. They are hillmen all. During the wet season of each year they keep to the higher ranges of the Cordilleras. They avoid sharp ridges and glaciers and feed in the meadows which these mountains clothe with a scanty herbage. With the coming of heat the mountain plants dry up. The vicufias then descend from the heights in search of food.

Soft-footed like the Arabian camel, they are extremely agile in the places they choose for life and liberty. Though the tribe is renowned less for sagacity than toughness, they have the wit to set sentinels to guard the feeding herds.

The guanacos are the larger, heavier species, massing in herds five hundred in number in the mountains, or reveling in the bleak discomfort of the plains of Patagonia. The llama which the ancient Peruvians domesticated was taken from the guanacos. The alpaca is the smallest, bred entirely for its woolly, hairy fleece. But the big tamed guanaco was indeed a wonder.

THE LLAMA, PACK HORSE OF THE ANCIENT PERUVIANS

For when Columbus reached America there was not a horse on all the vast twinned continent, and no animals had been tamed except the wolf, trained into a friendly dog, and, in South America, this useful beast, the llama.

The llama was the pack horse, the hackney and the beast of burden. The mysterious Peruvians had added several remarkable features to their fantastic civilization. They had learned how to grow corn, coffee, cotton and cocoa; their weaving and pottery and gold-working were of a very high order; and above all, they had captured and done with the llama what the ancient East had done with the camel. The male llamas did the work and supplied flesh food; the females were kept for their milk; and, as we have seen, the alpacas were the fleece-bearers.

THE CLEVER INCAS AND THEIR HERDS OF LLAMAS

The Incas had done as well in the breeding and perfecting of these animals for their several qualities as the old mystery men of the past had done, a thousand years before, in persuading sheep to grow flowing wool.
The alpaca’s long, fleecy coat makes finer, better wool than the llama wool. \Vool from the vicuña is the softest of all. Unfortunately it is becoming rare, and little of it reaches the market to-day.

The types that we know to-day were already fixed, high tribute to the skill of these early geniuses. It is thought that they themselves established the breed of guanaco, the one for weight-carrying and milk, the other cultivated for wool, as we have cultivated the jungle fowl for eggs. Llamas are still used to carry burdens.

Such is the story of the camel tribe. The camel has been taken about the world like cattle. It helped to carry up the wire which fenced in Australian farms from the devouring rabbit, and on the return journey it brought down wool to the ports. It toils in Zanzibar and has served in Italy; it is a valued servant in the Canaries and works for carrier and cultivator in many an odd corner of the world. Automobile and airplane have conquered the deserts, but the camels are useful still.

AN AMERICAN EXPERIMENT WITH CAMELS, WHICH FAILED

Just before the Civil War the United States Government attempted to use camels to carry supplies across the deserts of Arizona and New Mexico. The war interrupted the experiment, and many of the animals escaped For years hunters and prospectors saw them in the wilds, but it is believed that they have entirely died out.

Jumping beans come from Mexico and Central America. It is not the bean that jumps, but a little caterpillar inside. A tree which grows in swamps has curious three- cornered fruit divided into three parts, like little pods. In two of these pods are small black seeds the third part often contains a tiny caterpillar and is what we call the jumping bean. Before the tree can have its fruit it must, of course, bear flowers. A gray moth visits those flowers, and in part of each deposits an egg. The part which contains the egg grows with the rest of the flower, but, instead of becoming a pod for the seed of the tree, it turns into a home for the larva, or caterpillar, which is coming from the egg. Later the flowers lose their petals and seed-pods form and ripen. In August the seed is ripe. The husk containing the pods of seed and the little pod with the caterpillar inside drops to the ground and splits into three parts.

The caterpillar eats most of the inside of its house when it travels it coils itself up, then lets itself go like a catapult. carrying the house with it; or it rolls over and over. When the time comes for it to spin a coccoon and go to sleep, it does so. But first it cuts a door in the house, fastening it with silken threads. When its sleep is ended, and the caterpillar has turned into a moth, it cuts the threads that hold the door and crawls out of the bean-pod.