Then by Apollo's bidding led,
A wandering heifer following,720
Upon whose neck the dragging plow,
Nor the plodding wagon's curving yoke
Had never rested, he his quest
At last gave over, and his race
From that ill-omened heifer named.
From that time forth, the land of Thebes
Strange monsters hath engendered: first,725
That serpent, sprung from the valley's depths,