"Because I had to have something solid to rest my sticks against while I was building my walls, of course," replied Paddy. When I got the tops fastened together for a roof, they didn't need a support any longer, and then I dug it away to make this room. I couldn't have built such a big room any other way. I see you don't know very much about house-building, Cousin Jerry." "I--I'm afraid I don't," confessed Jerry sadly. CHAPTER XIII The Queer Storehouse. Everybody knew that Paddy the Beaver was laying up a supply of food for the winter, and everybody thought it was queer food. That is, everybody but Prickly Porky the Porcupine thought so. Prickly Porky likes the same kind of food, but he never lays up a supply. He just goes out and gets it when he wants it, winter or summer. What kind of food was it? Why, bark, to be sure. Yes, Sir, it was just bark--the bark of certain kinds of trees. Now Prickly Porky can climb the trees and eat the bark right there, but Paddy the Beaver cannot climb, and if he would just eat the bark that he can reach from the ground, it would take such a lot of trees to keep him filled up that he would soon spoil the Green Forest. You know, when the bark is taken off a tree all the way around, the tree dies. That is because all the things that a tree draws out of the ground to make it grow and keep it alive are carried up from the roots in the sap, and the sap cannot go up the tree trunks and into the branches when the bark is taken off, because it is up the inside of the bark that it travels. So when the bark is taken from a tree all the way around the trunk, the tree just starves to death. Now Paddy the Beaver loves the Green Forest as dearly as you and I do, and perhaps even a little more dearly. You see, it is his home. Besides, Paddy never is wasteful. So he cuts down a tree so that he can get all the bark instead of killing a whole lot of trees for a very little bark, as he might do if he were lazy. There isn't a lazy bone in him--not one. The bark he likes best is from the aspen. When he cannot get that, he will eat the bark from the poplar, the alder, the willow, and even the birch. But he likes the aspen so much better that he will work very hard to get it. Perhaps it tastes better because he does have to work so hard for it. There were some aspen trees growing right on the edge of the pond Paddy had made in the Green Forest. These he cut just as he had cut the trees for his dam. As soon as a tree was down, he would cut it into short lengths, and with these swim out to where the water was deep, close to his new house. He took them one by one and carried the first ones to the bottom, where he pushed them into the mud just enough to hold them. Then, as fast as he brought more, he piled them on the first ones. And so the pile grew and grew.