The question naturally arises, Why were the Greek dramatists so slow in increasing the number of actors? This was due partly to a paucity of histrionic talent and partly to difficulty in mastering the dramatic technique of the dialogue. In the dithyramb and the prehistrionic drama the poet was his own coryphaeus. Accordingly when Thespis introduced the first actor he served in that capacity himself, appointing another as coryphaeus. So did Phrynichus, Aeschylus, and the other dramatists of that period. Since there were then no retired actors and no opportunity to serve an apprenticeship, it is obvious that these early poets had to teach themselves how to act. At this stage it was not possible for anyone except a playwright to become an actor, and actors must have been correspondingly scarce. The situation improved somewhat after Aeschylus introduced the second actor, for though the poets still carried the major rôles it now became possible for men with natural histrionic ability to develop it and gain experience in minor parts. By the time of Sophocles, actors had become so plentiful, relatively speaking, that he could increase the number employed by each poet from two to three and could retire from personal participation in the public presentation of his works. His weak voice is said to have been responsible for this second innovation; but he occasionally appeared in scenes where this weakness was no great hindrance, e.g., as a harp player in _Thamyris_ and as an expert ball player in _Nausicaa_. By 449 B.C. the profession was so large and its standing so well recognized that a contest of tragic actors was made an annual event in the program of the City Dionysia. This course of development reveals one reason for the long duration of the one- and two-actor stages in Greek drama.