CHAPTER XVII.
Rumors of Danger From the Sioux Tetons .-- Ruthless Character of Those Savages .-- Pirates of the Missouri .-- Their Affair with Crooks and M'Lellan .-- A Trading Expedition Broken Up .-- M'Lellan's Vow of Vengeance .-- Uneasiness in the Camp .-- Desertions.-Departure From the Omaha Village .-- Meeting With Jones and Carson, two Adventurous Trappers .-- Scientific Pursuits of Messrs.

Bradbury and Nuttall .-- Zeal of a Botanist .-- Adventure of Mr.Bradbury with a Ponca Indian .-- Expedient of the Pocket Compass and Microscope .-- A Messenger From Lisa .-- Motives for Pressing Forward.
WHILE Mr.Hunt and his party were sojourning at the village of the Omahas, three Sioux Indians of the Yankton Alma tribe arrived, bringing unpleasant intelligence.

They reported that certain bands of the Sioux Tetons, who inhabited a region many leagues further up the Missouri, were near at hand, awaiting the approach of the party, with the avowed intention of opposing their progress.
The Sioux Tetons were at that time a sort of pirates of the Missouri, who considered the well freighted bark of the American trader fair game.
They had their own traffic with the British merchants of the Northwest, who brought them regular supplies of merchandise by way of the river St.Peter.Being thus independent of the Missouri traders for their supplies, they kept no terms with them, but plundered them whenever they had an opportunity.

It has been insinuated that they were prompted to these outrages by the British merchants, who wished to keep off all rivals in the Indian trade; but others allege another motive, and one savoring of a deeper policy.

The Sioux, by their intercourse with the British traders, had acquired the use of firearms, which had given them vast superiority over other tribes higher up the Missouri.