Mary Beth Cotrupi, age 10, of Newport News, Virginia, for her question:

Is it true that all animals are color blind?

Scientists suspect that a cow cannot see colors and neither can a cat. But fishes enjoy a watery world of rainbow colors. The hummingbird selects red flowers from his range of color vision and certain insects may sense colors that we cannot see. The study of animal vision is fairly new    but already we know for sure that all the animals are not color blind.

The bat senses sonar signals too high for human ears, the earthworm senses light with his skin, the katydid's ears are near his knees. The study of animal senses is a very up to date field of biology. It offers young nature lovers all sorts of fascinating future careers. Nature has distributed among her children countless different sense organs for seeing and hearing, smelling and tasting. Each type of seeing animal has special eyes to meet his special needs. When we learn what they can see, we get a better understanding of their points of view:

So far as we know at present, Miss Puss views the scenery in light arid dark shades of grey. However, the cat's eyes have another gift. She has special lenses that double the intensity of light and dark areas. This enables her to see when the light is very, very dim. The vision of horses, pigs and sheep also is limited to various shades of greys. The dog also has black and white vision, so a color TV is wasted on him. Cattle also see only in blacks and whites    which makes you wonder why a bull charges a waving red flag. The fact is, the hot tempered fellow charges any waving object. Against a dark background, a waving white flag would make him even madder because white is brighter and would stand out more.

You might call these various black and white visions color blindness: However, in human vision color blindness means something quite different. A color blind human tends to confuse certain shades of red, green and yellow. Avery few people see a colorless world in shades of dark and light grey. They are said to have achromatic, or non color vision. Rather than saying that dogs and cats are color¬blind, it might be more correct to say that they too have achromatic vision. (It also sounds more important.)

In the world of nature, a lot of surprising animals do have color vision, some¬times superior to ours. Of the mammals, several members of the monkey clan seem to see colors very much as we do. However, some of them have colorblind spots. Certain wide eyed little lemurs are blind to red. To them, the light of a red lamp changes the scenery to dark midnight, even in broad daylight. Being night animals, they wake up and become active under a red light.

Frogs and salamanders appear to have achromatic vision and dwell in a colorless world. But most of the scaly reptiles have color vision and so do the unblinking fishes. The leggy octopus views his watery world through human type eyes and his color vision is much like ours. The busy, daytime birds also enjoy a colorful world. Many insects also see colors, though most of them see the greens sad blues more clearly. Ants, for example, do not see the reddish colors.

Our color vision is limited to the wave lengths revealed in the rainbow spectrum. Our eyes cannot perceive the shorter wave lengths of ultraviolet light. But maybe certain animals can do this. Our eyes see the graceful swallowtail wags of a lunar moth as delicate green, But under ultraviolet light, the female looks very light and the male very dark: Maybe these insects see colors in the ultraviolet range, which is more than we can do. If so, Mrs. Ammoth sees her husband as a brunette and he sees bar as a blonde.