Chatterer nodded. He was still mumbling to himself angrily and wasn't polite enough to make a reply. Old Mother Nature took no notice of this. “What you have told us is good as far as it goes,” said she. “You said that Happy Jack is all gray excepting underneath. Usually the Gray Squirrel is just as Chatterer has described him, but sometimes a Gray Squirrel isn't gray at all, but all black.” Peter Rabbit's ears stood straight up with astonishment. “How can a Gray Squirrel be black?” he demanded. Old Mother Nature smiled. “That is a fair question, Peter,” said she. “Gray Squirrel is simply the name of Happy Jack's family. Sometimes some of the babies are born with black coats instead of gray coats. Of course they are just the same kind of Squirrel, only they look different. In some parts of the country there are numbers of these black-coated Squirrels and many think they are a different kind of Squirrel. They are not. They are simply black-coated members of Happy Jack's family. Just remember this. It is the same way in the family of Rusty the Fox Squirrel. Some members are rusty red, some are a mixture of red and gray, and some are as gray as Happy Jack himself. Way down in the Sunny South Fox Squirrels always have white noses and ears. In the North they never have white noses and ears. Rusty the Fox Squirrel is just a little bigger than Happy Jack and has just such a handsome tail. He is the strongest and heaviest of the Tree Squirrels and not nearly as quick and graceful as Happy Jack. Sometimes Rusty has two nests in the same tree, one in a hollow in a tree for bad weather and the other made of sticks and leaves outside in the branches for use in good weather. Rusty's habits are very much the same as those of Happy Jack the Gray Squirrel, and therefore he likes the same kind of surroundings. Like his cousin, Happy Jack, Rusty is a great help to me.” Seeing how surprised everybody looked, Mother Nature explained. “Both Happy Jack and Rusty bury a great many more nuts than they ever need,” said she, “and those they do not dig up sprout in the spring and grow. In that way they plant ever so many trees without knowing it. Just remember that, Chatterer, the next time you are tempted to quarrel with your cousin, Happy Jack. Very likely Happy Jack's great-great-ever-so-great grandfather planted the very tree you get your fattest and best hickory nuts from. “Way out in the mountains of the Far West you have a cousin called the Douglas Squirrel, who is really a true Red Squirrel and whose habits are very much like your own. Some folks call him the Pine Squirrel. By the way, Chatterer, Happy Jack forgot to say that you are a good swimmer. Perhaps he didn't know it.” By the expression of Happy Jack's face it was quite clear that he didn't know it. “Certainly I can swim,” said Chatterer. “I don't mind the water at all. I can swim a long distance if I have to.”