Guides were ordered to be furnished by the inhabitants, to show the detachment the way across the solitary and desert country. The detachment was to consist of horsemen entirely, that they might advance with the utmost celerity. To get as efficient a corps as possible, Alexander dismounted five hundred of the cavalry, and gave their horses to five hundred men--officers and others--selected for their strength and courage from among the foot soldiers. All were ambitious of being designated for this service. Besides the honor of being so selected, there was an intense excitement, as usual toward the close of a chase, to arrive at the end.