Cochrane moved to see. The dusk had deepened still more. The smooth, green-covered ground had become a dark olive. Where bare hillsides gave upon the sky, there were dark masses flowing slowly forward. The edges of the hills turned black, and the blackness moved down their nearer slopes. It was not an even front of darkness. There were patches which preceded the others. They did not stay distinct. They merged with the masses which followed them, and other patches separated in their places. All of the darkness moved without haste, with a sort of inexorable deliberation. It moved toward the ship and the valley and the gushing fountain and the stream which flowed from it. "What on Earth--" began Cochrane. "You're not on Earth," said Jones chidingly. "Al and I found 'em. You asked for buffalo or a reasonable facsimile. I won't guarantee anything; but we spotted what looked like herds of beasts moving over the green plains inland. We checked, and they seemed to be moving in this direction. Once we dropped down low and Bell got some pictures. When he enlarged them, we decided they'd do. So we lined up where they were all headed for, and here we are. And here they are!" Cochrane stared with all his eyes. Behind him, he heard Bell fuming to himself as he tried to adjust a camera for close-up pictures in the little remaining light. Babs stood beside Cochrane, staring incredulously. The darkness was beasts. They blackened the hillsides on three sides of the ship. They came deliberately, leisurely onward. They were literally uncountable. They were as numerous as the buffalo that formerly thronged the western plains of America. In black, shaggy masses, they came toward the spring and its stream. Nearby, their heads could be distinguished. And all of this was perfectly natural. The cosmos is one thing. Where life exists, its living creatures will fit themselves cunningly into each niche where life can be maintained. On vast green plains there will be animals to graze--and there will be animals to prey on them. So the grazing things will band together in herds for self-defense and reproduction. And where the ground is covered with broad-leaved plants, such plants will shelter innumerable tiny creatures, and some of them will be burrowers. So rain will drain quickly into those burrowings and not make streams. And therefore the drainage will reappear as springs, and the grazing animals will go to those springs to drink. Often, they will gather more densely at nightfall for greater protection from their enemies. They will even often gather at the springs or their overflowing brooks. This will happen anywhere that plains and animals exist, on any planet to the edge of the galaxy, because there are laws for living things as well as stones.