A drama is the imitation or representation of the conditions or situations (avasthānukṛti) [610] in which the personages who form the subject of treatment are placed from time to time, by means of gesture, speech, costume, and expression, and, one version of the definition adds, the situations must be such as to produce pleasure or pain, that is, they must be tinged with emotion. It is the presence of these ancillaries which distinguishes the drama from an ordinary poem; a poem appeals to the ear only, a drama is also a spectacle to delight the eyes; hence the term Rūpa or Rūpaka as applied generically to the drama, for Rūpa primarily denotes the object of vision, though the Indian tradition gives the artificial explanation that Rūpaka denotes a drama because the actors are credited with different parts. Further light is shown on the nature of drama (nāṭya) by the discrimination of it from dance (nṛtta) and mimetic art (nṛtya), which united with song and speech serve to make up the drama. [611] The dance is based on time and rhythm; the mimetic art is concerned with representing the feelings or emotions (bhāva), while the essence of the drama is the sentiment (rasa) which it evokes in the spectator, a fact which places it on a higher level than either of its handmaidens. But there may be dramas in which these auxiliaries take first place, and on this fact is based a distinction between the primary forms, Rūpakas, in which the poetry is the dominant element and the secondary forms, Uparūpakas. Of Rūpakas ten are distinguished, Nāṭaka, Prakaraṇa, Bhāṇa, Prahasana, Ḍima, Vyāyoga, Samavakāra, Vīthī, An̄ka, and Īhāmṛga, which vary in regard to subject-matter (vastu), hero or heroine, and sentiment. 3. THE SUBJECT-MATTER AND THE PLOT