“And so, quite often, Perry, when I walk up and down the silent canyons, round and round the lonely buttes, as I go climbing and scrambling in the sun, I stop and wonder if sometime I may not see a shadowy figure such as the Indians would have loved, stride across the sky. [Illustration: _Courtesy of American Museum of Natural History._ MUSEUM CAMP IN WYOMING BAD LANDS.] [Illustration: _Courtesy of American Museum of Natural History._ THE LARGEST OF THE TITANOTHERES. Brontotherium, male, female and young, from the rocks of the Wyoming Bad Lands. The largest Brontotherium was almost as tall as an elephant and fourteen feet long.] “And then, Perry, a brown stain in a rock changes the nature of the dream and the world and the life of three million years ago comes surging across my mind instead. It was when I was thus dreaming on my second day here that I found a wonderfully perfect specimen of the very first dog in America, the Procynodictis. That was worth finding.” “Dogs as early as the Washakie formation!” exclaimed Perry in surprise. “I thought dogs were as new as bears!” “Not in America,” Antoine answered. “The bear is a very late arrival into this country. It is possible that the Cave Man in America was here as early as the Cave Bear, although there were smaller bears in Europe long before. But Procynodictis was almost a direct ancestor of the dog, although, of course, he was a good deal like a cat, too.” “A cat and a dog at the same time,” exclaimed Perry, laughing; “that’s mixing up the breeds, sure enough.” “There was a regular cat-dog,” the other remarked, “and cat-dogs, such as Daphaenus, were very plentiful in America during the Oligocene Period. They had the teeth and jaws of dogs or wolves, but their claws were like those of a cat and could be drawn out and in, or partly, at least.” “How big was the one you found, Antoine?” “My Procynodictis was just a little larger than a domestic pussy, but with a smaller body, and longer legs. That combination of dogs’ teeth and cats’ claws should have been very effective, Perry, but I suppose it was too much of a good thing. Anyway, the cat-dogs died out, when the true cats and the true dogs came on the scene.” “It’s queer,” said Perry thoughtfully, “how that Eocene Period seems to have been a time of mixtures.” “It was a time of mammal branchings,” the young paleontologist reminded him, “the time when the types of to-day began to diverge. What two animals look more unlike each other to-day than a cat and an otter? Yet cat-otters, then, were as plentiful as cat-dogs. They were as big as a Hyrachyus, and considerably heavier.