"Each scale is fixed into the skin in front only; the rest of the scale is loose and overlaps the next one behind it. As the fish moves through the water every scale is pressed closer and closer to its body, and there is nothing to hinder its movements.""Why, that"s almost exactly like the feathers on the bird"s body," said Norah. "They all point backwards, so that the bird shall have nothing to hinder its flight through the air.""That"s a good girl," said Fred. "Now I will tellyou one thing more about the coat of the fish. Youknow if you take a fish in your hand it feels slimy and slippery. Teacher says the fish sends out over its body a slimy oil, which helps it to glide smoothly and easily through the water."SUMMARY
Fishes have cold blood, because they can take in only small quantities of air by means of their gills. They do not want a warm coat. Their clothing is formed of scales. Each scale is ?xed into the skin in front only. The scales overlap one another, press close to the body, and help the ?sh in its movements.
Lesson 36
Balloons
"I little thought," said Willie, "where teacher was going to lead us when he asked us to tell him all we could of the uses of coal-gas. Did you, Fred?""