The stadium[433] or racecourse of the Greeks was the natural development of that primitive type of race which is described in Homer, and which we may still see at school treats and rustic meetings. The competitors, drawn up in a line, race to some distant point which is the finish, or, turning round this point, race back again to the starting-point. Here we have the germ of the stade or straight race, and of the diaulos, and other turning races, as the Greeks called them (κάμπειοι). The start is marked by a post (νύσσα) or by a line drawn in the sand (γραμμή), and the finish or turning-point (καμπτῆρες) by a similar post or by some natural object, a stone, or tree-stump. From this primitive course two types of racecourse are derived. Both differ from the modern oval course in that they are long, narrow, and straight, the runners not describing a curve but running straight up and down the track. The first, which we may call the hippodrome type, is that in which the runners race round two posts placed at either end of the course and connected by one or more intermediate posts, or by a low wall called by the Romans the “spina.” One or both ends of the course were rounded off for the convenience of spectators, and this circular end was known as the σφενδόνη. This form was long regarded as the regular type of the Greek racecourse; but recent excavations have rendered it probable that though used by the Greeks for horse-races it was not employed by them for the foot-race, at least until Roman times. The true Greek stadium, as we now know, was strictly rectangular, both starting-point and finish being marked by parallel lines of stone slabs (βαλβίς, βατήρ), and even the seats at the end following the same lines. For such a course any fairly level plain was suitable; but for the convenience of spectators it was natural to select some level stretch surrounded on one or more sides by some rising ground, along the foot of a hill as at Olympia, or in a dip between two hills as at Epidaurus or Athens. All that was required in such cases was to level the ground for the actual track, and to improve the natural standing-ground by an artificial embankment, which might or might not be afterwards provided with seats. Most of the stadia in Greece, says Pausanias, were formed by such an embankment;[434] it was not till a comparatively late period that the seats were built up on masses of masonry and surrounded by walls and colonnades. The length of the actual track was always a stade or 600 feet; but, as there was no universal standard of measurement, the length of the stadium varied locally with the length of the foot.