In his works Plato never makes himself a part of the dialogues nor does he claim that he heard any of the dialogues. While in some dialogues there is no narrator, in other Socrates is speaking to some unknown friend as a first person. Three dialogues (Phaedo, Symposium, and Theaetetus) were narrated by students of Socrates, as distant memories. Phaedo is an account of Socrates' final conversation and hemlock drinking, narrated by Phaedo to Echecrates. Symposium is a narration by Apollodorus to Glaucon, of a story that took place when he was an infant. With the exception of Theaetetus, there is no mention how this oral transmission of dialogues was known to Plato.