As the enemy approached one of the oxen, usually the oldest bull in the herd, dashed out from his place in the square and bounded towards the foe, with head down, horns brandished with sidelong tosses of the head, snorting and bellowing defiance. As he left the square the ranks closed up and remained so until he returned, when the ranks opened enough for him to back into his place, while another charged out to carry on the combat in front of the square. These movements were executed with lightning rapidity, every animal dashing out in turn to seek single combat, the one to advance being always the one to the right of the returned champion. Usually the advance was for a distance of a dozen yards, but there were occasions when the explorers saw the challenging ox advance over a hundred yards from the main body. When there were sufficient bulls in the herd to form the outer lines, the cows were placed, with the calves, inside the square; but if the bulls were not numerous enough to complete the outer ranks, then the cows took their places beside the bulls. In one instance, where the herd consisted of cows and calves only, the cows formed the square and carried on the fight while the calves were sheltered within. The courage displayed by the oxen was not restricted to their defence. They appeared to be actuated by an _esprit de corps_ which could only be likened to the heroism which animates men of fanatical fighting tribes. They were apparently incapable of fear, even to that extent which makes the saving of one's self a first consideration. When the square was once formed it never broke. Every beast in it might be killed, one by one, but there was never a sign of a break-away or a stampede. If only a few were killed, the square stood its ground until the attackers retreated, when, with an open field, the square slowly retired, still in formation, and still ready, at the first signal, to halt and renew the fight. In one instance, where every beast had been shot save one, that one made his sortie, pranced round in defiance, and retired to the heap of slain, all that remained of his gallant comrades.