"Young men," said the Doctor, from his saddle, "you have seen a beautiful illustration in the theory of development. The hound and the antelope may have been originally an oyster and a worm. From their first slow motion, when one only opened its jaws to seize the other, they have progressed until the speed of to-day results. Should the hound ever become wild, and pursuit and flight change to an every-day matter instead of a holiday-sport, development would still continue. A giraffe-like antelope, with the speed of the wind, would fly before a hound the size of a stag." The Doctor's "clinic," as Sachem called it, was suddenly cut short at this point by a struggle for mastery between himself and the human spirit concealed in his horse. "How much," exclaimed the Professor, when Pythagoras had at length come off triumphant, and we again moved forward--"How much the race that we have witnessed is like that we all run. Powerful and eager as the greyhound, man sees flying before him, on the plain of life, an object which he thirsts to grasp. Taxing every muscle in pursuit, panting after it over the smooth country below the 40th mile-post, he crosses there the ravine where rheumatism and straggling gray hairs lurk, and with these clinging to him, starts up the hill of later life. Half-way to its summit, on which the three-score stone marking the down-hill grade looks uncomfortably like that over a tomb, he seizes the object of pursuit only to be flung back by it bruised. If of the proper metal, he falls but to rise again, and should the first wish be out of reach, fastens on one of its companions. There is where blood tells. If the least taint of cur is in it the first blow sends its recipient yelling to his kennel, there to whine for the remainder of life over bruised ribs." Muggs thought a single toss was sufficient, and retreat then only prudence. If the bones on one side were broken, he saw no reason to expose the other. Dying successful was only procuring meat for others to enjoy. The Professor was developing a remarkable talent for finding not only the stones of the past written all over with a wonderful and translatable history, but also the moral connected with each incident of our journey. Had any of us broken our necks he would doubtless have improved the occasion to draw a comparison and have made it the text of a philosophic disquisition. CHAPTER XIII. CHARACTER OF THE PLAINS--BUFFALO BILL AND HIS HORSE BRIGHAM--THE GUIDE AND SCOUT OF ROMANCE--CAYOTE VERSUS JACKASS-RABBIT--A LAWYER-LIKE RESCUE--OUR CAMP ON SILVER CREEK--UNCLE SAM'S BUFFALO HERDS--TURKEY SHOOTING--OUR FIRST MEAL ON THE PLAINS--A GAME SUPPER.