ANIMALS

Evening Post, Volume CXVIII, Issue 96, 20 October 1934, Page 5

ANIMALS

A PRISON REVOLT

THEY USE PARACHUTES

HOW FISHES GLIDE

The Avoid "flying" prefixed to, the names of numbers of animals is often I misleading.-^Flving squirrels, flying phalangers, flying lemurs, and the like are really parachutists. I With the exception of certain aquatic forriis parachuting animals happen also to bo tree-dwellers, and it is reasonable to suppose that in the distant past the habit of jumping from bough to bough gave rise to small structural modifications, the retention and elaboration of which produced effective parachuting organs. Our common squirrel possesses amazing leaping powers, considering that, except for a little flattening, the body is normal, and it is evident that a slight exaggeration of this flattening would materially increase the length of the leaps in space. This is what has happened in the case of the flying squirrels of Asia, Africa, and America. A surplus of furcovered skin has been developed along the sides of the body, stretching between the limbs and attached to them. Normally, when the animal is at rest, this skin ' falls into baggy folds, like an ill-fitting garment, but. when a leap is taken and the legs are spread the membrane is drawn taut, enabling the squirrel to "plane" to earth gracefully for a distance of seventy yards or more and to alight as if fitted with the most efficient shock-absorbers. MARSUPIALS THAT GLIDE. Squirrels 4ire not, however, the only mammals that have taken to this mode of life. Similar extensions of skin are found in the cobego, an insectivorous mammal with a membrane reaching to the very tip of its tail, and also.in the flying phalangers, -which are marsupials allied to the" opossums. Typical members of these unrelated groups are totally dissimilar in appearance, but it is remarkable that those forms which have been specialised for parachuting have become so strikingly alike as to convey the impression of close relationship. As a matter of fact, the flying phalangors of Australia are commonly spoken of as "flying squirrels" because the likeness to these animals is so marked as to obscure the fact that they possess the abdominal pouch which is the hallmark of a marsupial. These Australian types vary considerably in size and structure. The largest is the taguan of Queensland and Victoria, which measures 20 inches to the root of the tail, but tho most wonderful species is the pygmy aeroplaner. This is one of the smallest and most elegant of mammals, being about the size of a small mouse and having Jong, silky fur. It feeds upon honey and small insects, and its agility in Soaping from branch.to branch is said to bo. marvellous.' ' , ... .. .. VARIATIONS. The structures which operate as parachutes do not exhibit great-variation; i a lateral exteusion of the body in most cases provides all that is required. But there are a few interesting variants. In the Malay Peninsula there lives a richlycoloured "lizard about eight inches long, called the "flying" dragon," which performs its aerial "evolutionsi by the aid of semi-transparent"'''' Wings "of skm ; theso project frohv the sides of the body much like the wings of a butterfly, and can be folded back when not in use. This membrance agrees with those already described in being an extension of the body covering, but differs in being unattached to the linibs, and therefore dependent Upon other means to render it taut. This essential rigidity is provided by the ribs, six of which, on either side, are greatly elongated so as to traverse and support the- membrane like tho ribs of a fan. Flying fishes* of which there are more than forty species, are the most discussed of all gliders. In every case they are supported in the air by a pair of voluminous breast fins which are spread to act as planes as tho fish leaps from the water —the initial, velomty, derived from vigorous lashing of the tail in the water, being such that glides of more than 300 yards are possible. TRUE FLIGHT. Parachuting animals, however expert they may be, can only remain in the anfor a few seconds and have no power to reascend, but flying animals, having organs which not only support but also propel, can remain on the wing for an almost indefinite period and perform the most complex evolutions. The power of flight has been acquired by three widely distinct groups of living animals—birds, bats, and insects. Each has solved the problems in its own way. The: wing of a bird is simply a fore-limb containing all the elements ,of the human arm, but highly modified for the special role it has to play. In the course of evolution two fingers of the hand have been lost, and two of the remaining three have fused into a rigid plate fitted to co-operate with the other bones as a foundation for the wing feathers. Birds ar» unique in the possession of feathers, and the mechanism which can automatically transform the folded limb into an unbroken feather sheet, in a fraction of a second, merely by the act of extension, is one of tho wonders of Nature. To afford sufficient attachment for the great muscles of flight, the breast-bone of a bird is large and carries a deep keel along its middle. This keel varies in ' size as ■ the muscular - equipment varies, and is absent altogether in flightless birds like the ostrich. In bats, as in birds, it is the forelimbs that shoulder the burden of flight, but instead of the fingers being reduced they are enormously elongated to form supports for the skin membrane which constitutes the wing and stretches from neck, to tail. The effect produced is that or a great hand with completely webbed fingers. Tho wings of insects differ fundamentally from all others. They have arisen as fold-like outgrowths of the body wall, and are actuated by powerful muscles as the base only. Usually there are _two pairs,-but the diptera, pi1 flies, have' only one pair, the others -ha-ving been reduced to small stalked "balancers." 'Some wings .are rigid structures, as,in. butterflies; others can be folded up like a map and neatly packed away when not in use. A lightbodied insect having ample wings requires only to move them in a comparatively leisurely manner in order to fly, but when the wings are small in relation to the body immense rapidity of movement is essential—sometimes as many as 300 beats to the second.

Panic seized Venice at 11 o'clock on the night of July 17, when the new prison on Giudecca Island was seen to be in flames. Sounds of shots and revolver shots carried across the quiet lagoon added to the confusion. The fire is stated to have been started by the convicts. With wild cries the prisoners attacked the warders in an attempt to escape. Some got as far as the shore, and threw themselves into the lagoon, but were dragged back. After a struggle, the military guards, reinforced by troops from the mainland, managed to get the rioters into a large square and guard them with bayonets and revolvers until daybreak, when they were removed to the mainland. The fire was well in hand by 4 o'clock, but the prison was a wreck. The preliminary investigations suggested that the convicts plotted to set the building alight as a protest against the irnn discipline In which, they say. I'hey have been subjected.