Mr. Sachem and Mr. Muggs had been lying close behind me in their blankets. The former had given a terrified snort, and then both lay motionless. After the alarm, Sachem admitted that he was frightened. Had always heard that people shot over instead of under the mark in battle. Was resolved to lay low. Had no high views about such things. Muggs had not thought it worth while to get up. Knew they were wolves. Had heard more hextraordinary 'owls before he came to the blarsted country. But where was the doctor? Echo answered, "Where?" "Hallo, Doctor!" cried the guide, and a voice from the woods, which was not echo, answered, "Coming!" Again Buffalo Bill lifted his voice in the solitude, and again came an answer, this time in a form of query, "Is it developed, my boy? If so, classify it." And we answered that the birth in the air had developed into wolves, and been classified as the _canis latrans_, noisy and harmless. Finding that this new lesson in natural history had taken away all desire for sleep, I finished the study by the fire, with our guide for a tutor. The cayote (pronounced K[=i]-o-te), in its habits, is a villainous cross between a jackal and a wolf, feasting on any kind of animal food obtainable, even unearthing corpses negligently buried. With the large gray wolf, the cayotes follow the herds of bison, generally skulking along their outskirts, and feeding upon the wounded and outcasts. These latter are the old bulls which, gaunt and stiff from age and spotted all over with scars, are driven out of the herd by the stout and jealous youngsters. Feeding alone, and weak with the burden of years upon his immense shoulders, the old bull is surrounded by the hungry pack. But they dare not attack. One blow of that ponderous head, with the weight of that shaggy hump behind it, is still capable of knocking down a horse. The veteran could fling his adversaries as nearly over the moon as the cow ever jumped, if they only gave him a chance. Like a grim old castle, he stands there more than a match for any direct assault of the army around. [Illustration: MIDNIGHT SERENADE ON THE PLAINS.]