The drama has had a rich and varied development in India, as is shown not only by the numerous plays that have been preserved, but by the native treatises on poetics which contain elaborate rules for the construction and style of plays. Thus the Sahitya-darpana, or "Mirror of Rhetoric," divides Sanskrit dramas into two main classes, a higher (rupaka) and a lower (uparupaka), and distinguishes no fewer than ten species of the former and eighteen of the latter. The characteristic features of the Indian drama which strike the Western student are the entire absence of tragedy, the interchange of lyrical stanzas with prose dialogue, and the use of Sanskrit for some characters and of Prakrit for others. The Sanskrit drama is a mixed composition, in which joy is mingled with sorrow, in which the jester usually plays a prominent part, while the hero and heroine are often in the depths of despair. But it never has a sad ending. The emotions of terror, grief, or pity, with which the audience are inspired, are therefore always tranquillised by the happy termination of the story. Nor may any deeply tragic incident take place in the course of the play; for death is never allowed to be represented on the stage. Indeed nothing considered indecorous, whether of a serious or comic character, is allowed to be enacted in the sight or hearing of the spectators, such as the utterance of a curse, degradation, banishment, national calamity, biting, scratching, kissing, eating, or sleeping. Sanskrit plays are full of lyrical passages describing scenes or persons presented to view, or containing reflections suggested by the incidents that occur. They usually consist of four-line stanzas. Çakuntala contains nearly two hundred such, representing something like one half of the whole play. These lyrical passages are composed in a great many different metres. Thus the first thirty-four stanzas of Çakuntala exhibit no fewer than eleven varieties of verse. It is not possible, as in the case of the simple Vedic metres, to imitate in English the almost infinite resources of the complicated and entirely quantitative classical Sanskrit measures. The spirit of the lyrical passages is, therefore, probably best reproduced by using blank verse as the familiar metre of our drama. The prose of the dialogue in the plays is often very commonplace, serving only as an introduction to the lofty sentiment of the poetry that follows.