Rose Hutson, age 15, of Spencer, Oklahoma, for her question:

Is it true that a hippo sweats blood?

Some of our zoos have special quarters for a hippopotamus and visitors crowd around ' the special attraction. After all, Mr. Hippo has the biggest mouth in the world and we want to see it. His zoo home, as a rule, is a glass walled chamber of moist, warm air with a hippo sized pool for dunking and an area of dry slabs for sun bathing. When out of the water, the hippo's skin tends to glisten with pinkish dew and the poor fellow seems to be sweating blood. But this is not so.

In the wilds he spends most of his time in and under the waters of a river. And you know what a long dunking does to your skin. The water steals its natural oils and moisture.

Your skin protests with wrinkled puckers and becomes very dry. The hippo has extra oil glands in his skin and they secrete an oily dew that happens to be tinged with pink. When in the river, this rosy brilliantine stops the water from stealing moisture from his skin.

When sun bathing, the same pinkish oil protects his water soaked skin from drying out in tie air. His special skin lotion oozes from oil glands and not from sweat glands. And the chemical that tinges it pink does not come from the hippo's blood supply.