"What nonsense! Always ask if you don't understand me. I meant that I have read about plants and animals altering in time to suit the place where they are. If dogs are taken up into the arctic regions they get in time to have a very thick fur under the hair; and if they are taken into a hot country like this, they have a very fine silky coat." "Do they now, sir?" said Ned. "Now I wouldn't have thought that a dog would have so much gumption. But I don't know, dogs are very knowing." "I don't think the dog has anything to do with it, Ned; it is a natural law. Now, if a fir tree is in a sheltered place, where the soil is deep and sandy, it grows to a tremendous size; but if the seed falls in a rocky place, where it has to get its roots down cracks to find food, and cling tightly against the cold freezing winds, it keeps down close to the ground, and gets to be a poor scrubby bush a few feet high, or less." "Then the trees have got gumption too, sir. That's better than being blown down." "I don't know about gumption, Ned; but it's the same with flowers. They grow thin and poor on rocks and stones, and rich and luxuriant on good moist soils, and--Hallo! where are the others? we mustn't be left behind." "Oh, we're all right, sir. They're only just ahead, and we can't lose ourselves, because all we've got to do is to go back along by the trickling water here. I'll shout if you like." "Oh no; I could blow my whistle, but I don't want to, because it would startle the doctor. He'd think there was something wrong." "Don't whistle him, sir. Here's a nice comfortable bit o' rock here; would you like to sit down?" "You're tired, Ned," said Jack quickly. "Am I, sir? Well, I dunno--p'r'aps you're right. I s'pose I am a bit fagged. Legs don't seem to go quite so well as they used. If you wouldn't mind, I think I should like just ten minutes' rest to freshen me up a bit." "Sit down then." "After you, sir." "Very well: there. No, sit down--or, better still, lie down on your back." "Make the things about puzzled, and want to know what I am. I shall be having snakes and lizards going for a walk up my arms and legs, sir. But I don't know as I mind for a bit--I'll risk it." Jack had halted at the foot of a perpendicular wall of moss-grown rock, and set the example, after disturbing the grass and ferns at the foot, of sitting down, and Ned lay at full length. "Lovely, sir," he said. "It's worth while to get regular tired so as to enjoy a rest like this. I don't s'pose they'll go much farther, and they must come back this way, I suppose." "I think so, Ned. They couldn't come back through the forest, and they would not as soon as they missed us, they'd be sure to come this way so as to pick us up." He was silent for a few moments, and then went on softly, as his eyes wandered over the trees and creepers about them--