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Subject: ‘Biology’

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Richard Owen was the first Director of the Natural History Museum

Posted in Biology, Famous landmarks, Historical articles, History, London, Medicine, Oddities on Thursday, 19 December 2013

This edited article about Richard Owen first appeared in Look and Learn issue number 498 published on 31 July 1971.

Richard Owen, picture, image, illustration
Professor Richard Owen

A threatening figure rises ferociously from among the trees. In the dusky half-light the monster rears up, but does not move. A few moments pass – but still it does not move. It never will, for it is a life-size model of an Iguanodon and it stands, huge and silent, with models of its fellow prehistoric dinosaurs in the grounds of a south London park.

The stone monsters of Crystal Palace, some of which still exist beside a miniature lake at Sydenham Hill, were the fanciful creations of the scientist Richard Owen. Owen was a leading anatomist in Victorian times and specialised in the reconstruction of animals from prehistory.

People are amused by the models today, and scientists may scoff at them, for they are largely inaccurate, and few remember the name of the man who caused them to be built in 1855. Their somewhat comic appearance is in direct contrast to Owen’s own personality, for he was a solemn, humourless man. But at the time, they were serious enough attempts to recreate the true appearance of the dinosaurs.

The funniest thing of all about these model monsters is the little known fact that before their erection at Crystal Palace, a dinner in honour of Richard Owen and other scientists was held inside the half completed structure of the supposed Iguanodon, the biggest of the models. It says something of the scale of this animal when one reads that 21 scientists sat down to a meal inside it! It must have seemed a curious occasion to Owen. His reputation in his own lifetime was never as high as he would have liked or, indeed, as he was entitled to by his achievements. Dinner in a dinosaur was an honour he probably found difficult to accept as a proper expression of esteem.

Owen was born at Lancaster in 1804. As a young man he accepted a temporary post as assistant to William Clift, the curator of the Hunterian Museum of the Royal College of Surgeons. So involved did he become with the museum and its collections of anatomical specimens, then the finest in the world, that he stayed there until 1856, having succeeded Clift as curator in 1849.

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The Black Death began its astonishing destruction in the East

Posted in Biology, Famous battles, Historical articles, History, Medicine on Tuesday, 26 November 2013

This edited article about the Black Death first appeared in Look and Learn issue number 462 published on 21 November 1970.

Siege of Kaffa, picture, image, illustration
A vast army of Tartars surrounded Kaffa in Abyssinia in 1346; suddenly, when it seemed that the city must surely fail, the plague broke out among the Tartar hosts, by James E McConnell

It was the golden age of chivalry, an age when gallant knights fought each other with lance and sword at tournaments, an age when England could look with pride at her king, Edward III, who had routed the Scots and inflicted crushing defeats on the French at Crecy and Calais. It was the year 1348. England’s wars with France and Scotland were over, and she was now prosperous and thriving on her large exports of wool and cloth. It was a time, then, for pride and for confidence in a bright future. And why not? Trade and Edward would surely look after England for a long time to come.

How wrong they all were, those proud English revelling in their prosperity. For, by the end of that fateful year, England was to see her population decimated and her country turned into a wasteland by an enemy far more terrible than any she had met on the battlefield.

The enemy came in the shape of an ordinary French sailor who had sailed with a fair wind to the coast of England. It is not known for sure where the sailor landed, but it is generally assumed that it was at Melcombe Regis, now Weymouth, which was an important port at that time. The fact that he was able to walk off the ship at all is surprising. For he carried within him the baccillus of the pestilence known as The Black Death.

The story of the “Death” in England, is only a very small part of the history of this terrible epidemic which raged across the whole of Europe, killing twenty five million people.

It had begun ravaging Europe in the autumn of 1347, but it had originated in the East several years earlier. It had been heralded by ominous reports brought back by travellers returning from distant Cathay and India with frightening stories of disasters, multiplying on each other with such rapidity that the credulous could only assume that they were a chastisement given by God to the heathens. These travellers’ stories were full of storms and earthquakes such as the world had never seen before. In China alone, there had been drought, famine and floods. There had been violent earthquakes, so severe that on one occasion a mountain had disappeared. There had been a swarm of locusts such as that which had been inflicted by Aaron on the Pharaoh for refusing to free the Israelites, and even worse, a noxious mist which had crawled across the land, destroying every leaf and blade of grass which lay in its path. Between Cathay and India, there had been a great rain of fire, and on the borders of India, people had suffered the horror of a downpour of serpents, lizards and frogs.

These first reports which filtered through to Europe were undoubtedly exaggerated, if not downright lies. But there was no doubt about one thing. Strange things were happening in the East.

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Men have died for the living jewels of the ocean

Posted in Animals, Biology, Fish, Nature, Sea on Tuesday, 12 November 2013

This edited article about ocean life originally appeared in Look and Learn issue number 454 published on 26 September 1970.

Coral reef, picture, image, illustration
Diver with Coral reef and angel fish by E S Hodgson

No jeweller’s shop window can compete in variety and depth of colour with the creatures that live beneath the sea. Some of these creatures actually supply the jewels and adornments that are found in jeweller’s shops.

Perhaps the most famous is the pearl oyster.

This small mollusc makes inside its shell the beautiful pearls which have adorned womankind for many centuries.

But why does it do this?

The answer is simple. It does it because it has an irritation and wants to get rid of it.

If a grain of sand or some other small article gets inside the shell of a pearl oyster, the oyster covers it with layer upon layer of a substance known as nacre, or mother of pearl. It stops only when the irritation has stopped and, by that time, the pearl may be of quite considerable size. It may also be a number of different colours – creamy-white, pink, or in very rare cases, black.

Pearl oysters are found attached to rocks by divers at depths of between 50 and 150 ft. Perhaps the best pearl divers in the world are Japanese women, for some of whom collecting pearls is a unique way of life.

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The Parrot fish sleeps in a slimy homemade sleeping-bag

Posted in Animals, Biology, Fish, Nature, Wildlife on Wednesday, 5 June 2013

This edited article about fish originally appeared in Look and Learn issue number 280 published on 27 May 1967.

Funny fish, picture, image, illustration
The Parrot fish changes its colour among the coral (bottom, centre)

Until about 40 years ago, the sleeping habits of fish were something nobody had ever really thought about. Zoologists knew that all animals need rest, but fish have no eyelids and as their eyes are always open, they appear to be constantly awake. Then one night, the director of the Aquarium at the London Zoo happened to go into the Aquarium. As he switched on the lights he saw at once that some fish, that by day swim in massed shoals, had separated. Each was lying motionless on its own on the base of the tank. Other fish were lying on their sides, and plaice were floating just off the bottom, instead of lying on the tank-floor, as they do by day.

In the years since then more attention has been paid to how fish spend the night, and many interesting discoveries have been made. Young soles live by day on the sea-bed. At night they come to the surface and float there fast asleep. Other fish rest on the bottom standing on their heads. But perhaps the oddest sleeping habits are found in some members of the large family known as parrot-fish. Many of these put on a kind of nightdress before going to sleep.

As night falls, each parrot-fish gives out slime from glands in its skin. During the day the fish gives out just enough slime to help it slip more easily through the water, but at night, in a way we do not yet understand, much more is given out and it forms a thin covering almost like a veil, completely surrounding the fish. This is not a careless or haphazard process, for on looking closely at the front of the veil, near the mouth of the fish, one sees that there is an opening. This is guarded by a flap that forms a valve, allowing water to enter the envelope-like case of slime. At the back of the veil there is another hole to let the water out.

These two holes mean the parrot-fish is able to draw water in through the front valve, gulp it down and pass it out through the gills for breathing. In the morning the parrot-fish breaks out of its nightgown and swims around as usual. The big mystery is why the fish should don this nightdress. One idea is that because parrot-fish live where the sea-bed is made up of fine sand, their gills might become silted up whilst they slept, and they would suffocate. Another idea is that the slimy envelope protects them from enemies whilst they are asleep and off guard.

Whatever the purpose may be, it is not something that the fish can do quickly, like slipping into or out of pyjamas or a nightdress. It takes half an hour for the fish to weave its veil, and another half an hour for it to break out of it in the morning, by biting at the slime and wriggling its body against it. It is easy to see that it must be something of a job breaking out of such unmanageable material, and one can imagine the difficulty an enemy of the fish would have breaking into it.

The mystery is deepened because not all parrot-fish put on this night-attire, and because those that do so, only use it under certain conditions. Nobody has yet discovered definitely, what those conditions are. To say the least this must be the strangest sleeping habit of any animal, and certainly one of the most puzzling.

The legend of the cockatrice or Basilisk

Posted in Animals, Biology, Legend, Superstition on Tuesday, 7 May 2013

This edited article about the basilisk originally appeared in Look and Learn issue number 245 published on 24 September 1966.

basilisk, picture, image, illustration
Helmeted basilisk

It sometimes happens, although very rarely, that an elderly domestic hen may begin to grow wattles and to crow while still laying eggs. It may also happen that an elderly barnyard cockerel may lay a kind of egg. These things merely indicate that the birds are undergoing a change of sex in later life.

These things were noted by people living many centuries ago. They did not understand what was happening, so to them such events seemed miraculous, and they invented a legend to explain them. The legend was that the egg laid by an elderly cockerel would hatch and from it would come a rather terrifying creature which was half cockerel, half serpent. This cockerel with a serpent’s tail they called a cockatrice or basilisk.

The basilisk was the epitome of everything evil and was said to be so deadly that, if it looked at a man, he would drop dead. It was generally believed that there were basilisks all over the country, in hiding.

There was, however, an ingenious knight who had the idea that, if he made a suit of armour composed of mirrors, he could rid the country of basilisks because, whenever he confronted one of them, the basilisk would see its own image in his armour and would itself drop dead!

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Living fossils hold clues to the evolution of insects

Posted in Biology, Insects, Nature, Prehistory, Wildlife on Monday, 29 April 2013

This edited article about insects originally appeared in Look and Learn issue number 234 published on 9 July 1966.

Primeval forest, picture, image, illustration
Huge dragonfly-like insects lived in prehistoric forests

Two questions which will probably occur to anybody who looks at insects in all their variety are: “Why are there so many of them?” and “Where did they come from?”

Study of the lives of insects gives us an idea as to why there should be so many, for every different sort does a particular job which is not done by anything else in the area in which it lives. The large numbers of different species can be accounted for by the limited abilities of each one, for there are few “Jack-of-all-trades” among insects.

To discover how insects came into being is much more difficult, for in the animal kingdom are many related creatures. Spiders and crabs, for example, both have jointed legs attached to a hard skeleton outside the body. But these are cousins, not ancestors, to the insects.

We know what the ancestors may have looked like, however, through the discovery of a “living fossil” type of animal, known from many tropical parts of the world. This is called Peripatus, or Velvet Worm, because its body is covered by a huge number of tiny bumps which look like plush.

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Hibernating animals hover between life and death

Posted in Animals, Biology, Fish, Nature, Wildlife on Friday, 22 February 2013

This edited article about hibernation originally appeared in Look and Learn issue number 152 published on 12 December 1964.

Hibernating animals, picture, image, illustration

A cutaway landscape showing hibernating animals by David Nockels

During the cold winter months you will sometimes find butterflies and moths hidden away behind curtains and pictures or in corners of rooms that are little used. They look quite dead, but if you move them carefully to some place that is warm you will see them gradually fluttering back into life.

In the same way, you may find a hedgehog buried in the leaves at the bottom of a ditch or rolled up in a ball under a garden shed. If you have a pet tortoise it will disappear in winter – unless you come across it in some sheltered spot drawn into its shell and to all appearance lifeless.

These are only a few of the many creatures who escape the cold of winter and manage without food by going into the deep sleep called hibernation.

The term “hibernation” comes from the Latin word hibernatus, meaning “winter quarters.” And that is exactly what hibernating creatures do: they go into winter quarters and sleep soundly until spring brings warmth again.

In countries of northern and western Europe and North America many animals find their supply of food cut off in winter and would starve. So they go into a long deep slumber, and keep themselves alive on the fat that has accumulated in their bodies when they were able to feed in the summer and autumn.

Unlike the birds, which can fly for thousands of miles to warmer lands where food is plentiful, most animals cannot travel long distances to places in search of food.

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The manatee could be mistaken for a mermaid

Posted in Animals, Biology, Fish, Legend, Nature, Wildlife on Wednesday, 20 February 2013

This edited article about the manatee originally appeared in Look and Learn issue number 146 published on 31 October 1964.

manatee, picture, image, illustration

Mermaid or manatee?

When nature designed the manatee she was not quite sure whether it was going to be a fish or a land-living animal. For although this queer creature spends all its life in the water it feeds by browsing on vegetation.

At one time zoologists thought it was a close but small relative of the whale. It has a fish-shaped body, forelimbs like paddles and the flat, horizontal tail of the whale.

But there the resemblance ends. The manatee has teeth, whereas the whale has none. It does not blow like a whale, but comes to the surface of the water to breathe just as a land animal would do. And even more unlike whales, it is not a deep-sea creature, seldom venturing far from the coast or the mouths of rivers.

Actually, the creature is closely-related to herbivorous (plant-eating) land animals such as the cow. It is thought that the ancestors of the manatee were land animals which through millions of years became specially adapted for feeding on underwater vegetation.

When the manatee periodically raises its head out of the water to breathe, it has a strangely human appearance. This probably gave rise to the legend of the mermaid. For that reason its Latin zoological name is Sirenia, from the Latin word, sirene, meaning “sea nymph.”

There are three species. One is native to South America, one to North America, and the third to the coast of West Africa. No adult species is more than eight feet long and all have a smooth, hairless skin.

The forelimbs or flippers are oval shaped and have three nails at the tips.

Manatees’ mouths are specially designed for cutting great swathes of underwater vegetation.

The upper lip consists of two bristly pads by means of which the weed is sucked into the mouth, where it is squeezed and pressed by horny plates on the palate. The process of chewing is helped by eleven pairs of cheek teeth in each jaw.

These teeth are constantly being renewed. They are arranged in such a way that as the front ones are shed their places are filled by teeth from behind. As the first teeth are used up before the last of the series has fully developed, only six teeth are functioning at the same time.

Manatees eat such enormous quantities of water weeds that in 1962 their appetites were exploited to clear thick growths of weeds which were choking the drainage ditches and canals in Georgetown, British Guiana.

A force of 70 of the animals was taken on the strength of the British Guiana Department of Drainage and Irrigation. When they were put to work in a badly-choked canal they relentlessly cut a swathe through the vegetation, so enabling the water to flow more freely.

When they reached the end of the canal the vegetation had grown again behind them. So the manatees turned and mowed it down again.

Travelling backwards and forwards along the canals, the aquatic lawnmowers can in a few hours clear an amount of weeds which it would take a gang of men several days to do. On one occasion two large ponds each covering an area of nearly 4,000 square yards and hopelessly choked with water weeds were cleared by three industrious manatees in a week.

Incidentally, the British Guiana manatees are the first marine animals that have been successfully domesticated by man and made to work for him.

Minuscule creatures in the garden pond

Posted in Biology, Nature, Science on Wednesday, 6 February 2013

This edited article about amoeba originally appeared in Look and Learn issue number 118 published on 18 April 1964.

crustaca, picture, image, illustration

Crustacea with the distinctive cyclops (centre)

When you look in a pond it seems to be alive with sticklebacks and minnows, tadpoles and newts, water beetles and snails. They seem very tiny indeed and there are a lot of them.

But if you examine a drop of water from the pond through a microscope you see a world of creatures tinier than the smallest fish or insect.

In this crowded, busy little world every speck of life keeps its microscopic body alive by feeding and by taking in oxygen and giving out carbon dioxide to “breathe” as do fish and land animals.

Every living thing in the drop of pond water is continually on the move. Some move slowly as though feeling their way about. Others cross and re-cross and dart backwards and forwards in a flurry of activity. You might be at the top of a skyscraper watching a street during the rush hour instead of looking at a drop of water.

Smallest of all these microscopic creatures are the amoeba, which are the most simple forms of animal life. There are several kinds of amoeba but each consists of a single speck of jelly-like substance which must be magnified about a hundred times by the microscope to be seen.

Some amoeba propel themselves through the water by means of minute, hair-like threads called cilia. These are constantly vibrating and set up currents in the water to push the midgets along. Other amoeba move about by pushing out from their bodies microscopic projections of jelly called pseudopodia, which cause them to glide or flow across the surface of the water.

Then there is the paramoecium, sometimes called the slipper animalcule because of its shape. A procession of two hundred of them marching in single file would be less than an inch long. Despite its small size, the paramoecium is covered with a kind of shell called a pellicle.

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Deep sea echo-sounding is modelled on bat behaviour

Posted in Animals, Biology, Nature, Science on Friday, 4 January 2013

This edited article about nature originally appeared in Look and Learn issue number 807 published on 2nd July 1977.

Bats, picture, image, illustration

Bats

Cuttlefish, trapdoor spiders, bats and glow-worms are only some of the members of the animal kingdom which “discovered” scientific facts long before Man

Powered by its jet engines, a Concorde sweeps several kilometres high across the Atlantic at twice the speed of sound (about 2,240 km per hour at a height of approximately 10 kilometres above sea level). Concorde is one of the greatest achievements in modern transport, but the principle of the engines that give the aircraft its fantastic speed is older than man himself.

Countless millions of years ago, a group of creatures called cephalopods were jet-propelling themselves through now forgotten seas. The most common cephalopods today are the cuttlefish.

Next time you visit a large aquarium or marine zoo look out for a cuttlefish. You will notice that, though it manoeuvres with its fins, when it is surprised it appears to be jet-propelled and moves through the water in a series of darting motions.

The secret of the cuttlefish’s jet propulsion is that it sucks water into its body through a wide opening in its head, called the mantle. As the water is sucked in, muscles in the mantle contract, so reducing the space for the water.

Contracting the muscles increases the pressure at which the water is held in the mantle. Increasing the pressure on the water causes it to squirt out at high speed through a narrow opening in the mantle. This opening is called the syphon. In fact the action is rather like squirting soda water from a syphon.

The cuttlefish’s motion is based on the same principle as that of rocket propulsion. As expanding gases shoot from the tail of a rocket, the force known as reaction causes the rocket itself to move forward. The cuttlefish’s water jet produces the same effect.

Turbo-jet engines that power aircraft work in exactly the same way. The only difference is that the jet engine uses a stream of hot and expanding gases.

Air is sucked in through the front of the engine and passes to a device called a compressor. The compressor then forces the air at increased pressure into a space called the combustion chamber. In the combustion chamber the air is mixed with a highly inflammable fuel and becomes very hot.

Heating the air and other gases makes them expand. As the gases expand, they struggle for more space in the combustion chamber and try to escape. The only escape route is through a nozzle at the rear of the engine.

Just as the cuttlefish is moved by the jet of high-pressure water forced out of its body, so the aircraft travels forward because of the high-pressure gases streaming from the rear of the engine.

Jet propulsion is just one of scores of devices which we use every day but which were really in use by animals before man ever thought of them.

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