He rode along in silence. "Why was the feeling so intense in the old days?" he inquired, after a time. "It was due to physical conditions," she replied--"the geography of the country. Water-holes were few and very far apart, and to get from one to another often entailed a journey impossible to a man without a horse. To steal his horse, therefore, was to deprive him of his sole means of getting to water--practically to deprive him of his life. If he didn't die of thirst, which frequently he did, at best it was a very grave offense. It isn't considered so now--not so much so, at any rate--unless in the desert wastes to the west of us. Yet the feeling still lurks within us, and a stolen horse is a matter that concerns the whole community." He nodded thoughtfully, but remained silent. Suddenly Helen drew rein. Before her was a horned toad, peculiarly a part of the desert, blinking up at them wickedly. He drew rein and followed her eyes. "A horned toad, isn't it?" Helen shook her head. "Are you interested in such things?" she inquired. "In a way--yes," he affirmed, doubtfully. "Though I can't see good reason for their existence." His eyes twinkled. "Can you?" Helen was thoughtful a moment. "Well, no," she admitted, finally. "Yet there must be a good reason. Reptiles must live for some good purpose. All things do--don't you think?" Then, before he could make a rejoinder, she went on: "I sometimes feel that these creatures were originally placed here to encourage other and higher forms of life to come and locate in the desert--were placed here, in other words, to prove that life is possible in all this desolation." He glanced at her. "Certainly it has worked out that way, at any rate," he ventured. "Good old Genesis!" He smiled. "It seems to have," she agreed, thoughtfully. "Because you and I are here. But it goes a long way back--to Genesis--yes. Following the initial placing, other and higher organisms, finding in their migratory travels this evidence of life, accepted the encouragement to remain, and did remain, feeding upon the life found here in the shape of toads and lizards--to carry the theory forward a step--even as the toads and lizards--to carry it back again--fed upon the insects which they in their turn found here. Then along came other forms of life, higher in the cosmic setting, and these, finding encouragement in the presence of the earlier arrivals, fed upon them and remained. And so on up, to the forerunners of our present-day animals--coyotes and prairie-dogs. And after these, primitive man--to find encouragement in the coyotes and prairie-dogs--and to feed upon them and remain. Then after primitive man, the second type--the brown man; and after the brown man, the red man; and after the red man, the white man--all with an eye to sustenance, and finding it, and remaining."