Category Biology

            A chameleon will change color when it senses danger. This remarkable member of family can change color to match its background or, at least to become almost unrecognizable.

            The ranges of color and patterns of the various species differ widely, but most chameleons can become yellow or cream, green or dark brown. They can also adapt spots either dark or light depending on the color of the ground.

            Apart from its response to danger, the chameleon will change color according to the light and temperature. This mechanism is controlled from the nervous system and involves the dispersion or concentration of color pigments in the creature’s skin.

          Group of elephants have been found buried together both in Africa and Asia. The nearness of the animals to each other may be no more than a coincidence. The areas may be no more than sites, since elevated and dried, where elephants have been drowned in   bags or while crossing river.

           However, many people will argue that old elephants, when their end is near, resort to their legendary “graveyards”. The discovery of the remains of a solitary elephant is rare. On the other hand a body in elephant country would usually soon disappear owing to the activities of natural scavengers.

           Most experts will accept that there is much truth in the old saying “An elephants never forgets”. It does have a retentive memory. Also, when an elephant is dying it is not uncommon for members of the herd gather round and try to revive it. When all hope is lost they encircle their relation as if in mourning at a funeral.

             Bees swarm in late spring in search of new home. During the winter the queen bee begins to lay her eggs and the colony sets about rearing its young. As the weather becomes warmer and the early flowers appear, the raising of young bees increases rapidly.

              By the end of spring the colony has become so overcrowded that a large number of the bees, including the old queen, leave the hive and establish a new queen emerges who will experience the same swarming instincts the following year. And so the cycle of activity goes on.

               Under water, frogs breathe through their skins. A frog is an amphibian. That is o say it lives both on land and in water. It has lungs, but it has no ribs and therefore cannot expand its chest and suck air into its lungs as do reptiles, birds and mammals. On land air is drawn in and out of the frog’s nostrils, which have valves in them, by pulsations of the floor of the mouth. The air is forced in and out of the lungs by contraction of the throat and body muscles. A frog’s mouth is always kept tightly closed and the   pulsations of throat vary from 120-140 a minute.

               Even on land the skin plays a greater part in breathing than the lungs. However, air can be absorbed only through a moist skin. If the skin becomes too dry, the frog will die. Therefore the skin contains glands which secrete a clear mucus or smile whose function is to keep the skin moist and supple. The skin absorbs water as well air, for frogs do not drink.

                Frogs are cold-blooded. That means they are as warm or as cold as the air or water surrounding them. In winter they hibernate under water, where their body temperature fails, their bodily functions are kept at a minimum and breathing is carried on entirely through the skin.

            A caterpillar starts to become a butterfly as soon as it enters the chrysalis stage, by wrapping itself in cocoon. During this phase, known as pupation, the insect gradually develop all the butterfly characteristics, including wings. For some butterflies the transformation may be completed in one or two weeks. But others need many months before they are ready to leave the cocoon and     fly away.

            From the time it is hatched to the time it starts the pupation stage, a caterpillar or larva does little more than eat, grow larger and moult several times. This larval stage varies according to the species. Small caterpillars will complete their development in a week but some large varieties will take us two years or more.

            When this period is over the caterpillars spins a cocoon under a leaf or even underground, and enters it to begin the transformation. Many cocoons are of silk.