Bobby Dean, Age 9, Of Victoria, B.C.., Can., for his question:
How does a chameleon change to match his surroundings?
The true chameleon lives in Africa and other warm countries of the old world. We do not often see him. The amazing fellow is a lizard, and most people imagine that he can change his skin from red to purple, from green to yellow in a flash to match his surroundings. But this is not quite true.
In a dark room, the chameleon's coat is yellow. It is also yellow when he squats on a white handkerchief in bright sunshine. If he happens to be sitting on a brown table in bright sunshine, his skin turns dark gray. So the chameleon's skin is not always a perfect match for his surroundings.
There are many colors that the amazing lizard cannot match at all. He can turn many shades of green or yellow. He can turn gray or almost black but he cannot match a red or a purple background.. The secret of this turncoat lies in his skin. It is like a layer of c1ear jelly stuffed with colored marbles of assorted sizes.
The little marbles are so very small that we need the magnifying power of a microscope to see them. Most of the little marbles in the top layer of jellified skin are yellow. Peeping through them, we see a 1ayer of black marbles and below them is a layer of white marbles.
Two things can happen to make the chameleon change from one color to another. The bottom layer of white marbles may act like a mirror and reflect the blue of the sky. The blue color shines up and blends with the yellow marbles at the top. Blue and yellow b1ended together make green. Our lizard looks green when he sits among the leaves on a sunny day.
He can also change the size of the black marbles in his skin. When light reflects from, say, a dark table top, the black dots grog and spread. The white layer at the bottom cannot mirror the blue sky because it is hidden. We see only the yellow marbles in the top layer of skin. The black marbles can grow bigger and spread fingers around the yellow marbles. When this happens, the skin of the chameleon becomes gray, then darker gray, then almost black.
The true chameleons do not live in America. But we sometimes call the little anole lizard a chameleon because he, too, can change the color of us skin. This pretty little creature can wear various shades of green or brown. His naturally green skin is speckled with black cells which can swell up or shrink to tiny dots. When the black cells become big, they blend with the green to make the anole look brown.