Diogenes Laertius IV.1
“These facts are as accurate details about Plato as we are able to gather in our laborious research of the things said about him. Speusippus, an an Athenian son of Eurymedon, took over for him. He was from the deme of Myrrhinos and was the son of Plato’s sister, Pôtônê.
Speusippos was the leader of the school for eight years, and he began after the 108th Olympiad. He had statues of the Graces dedicated in the Museion which Plato built in the Academy. Although he remained an adherent to Plato’s theories, he was not like him at all in his character. For he was quick to anger and easily induced by pleasures. People say that he threw a little dog into a well in a rage and he went to Macedonia to the marriage of Kassander thanks to pleasure.
Two women, Lastheneia of Mantinea and Aksiothea of Phlios, were students of Plato who are said to have heard Speusippus speak. Writing at the time, Dionysus says mockingly: “It is possible to evaluate your wisdom from your Arcadian girl of a student.” And, while Plato made everyone who came to him exempt from tuition, you “send everyone a bill and take money from the willing and unwilling alike!”
Τὰ μὲν περὶ Πλάτωνος τοσαῦτα ἦν ἐς τὸ δυνατὸν ἡμῖν συναγαγεῖν, φιλοπόνως διειλήσασι τὰ λεγόμενα περὶ τἀνδρός. διεδέξατο δ᾿ αὐτὸν Σπεύσιππος Εὐρυμέδοντος Ἀθηναῖος, τῶν μὲν δήμων Μυρρινούσιος, υἱὸς δὲ τῆς ἀδελφῆς αὐτοῦ Πωτώνης. καὶ ἐσχολάρχησεν ἔτη ὀκτώ, ἀρξάμενος ἀπὸ τῆς ὀγδόης καὶ ἑκατοστῆς Ὀλυμπιάδος· Χαρίτων τ᾿ ἀγάλματ᾿ ἀνέθηκεν ἐν τῷ μουσείῳ τῷ ὑπὸ Πλάτωνος ἐν Ἀκαδημείᾳ ἱδρυθέντι. καὶ ἔμεινε μὲν ἐπὶ τῶν αὐτῶν Πλάτωνι δογμάτων· οὐ μὴν τό γ᾿ ἦθος διέμεινε τοιοῦτος. καὶ γὰρ ὀργίλος καὶ ἡδονῶν ἥττων ἦν. φασὶ γοῦν αὐτὸν ὑπὸ θυμοῦ τὸ κυνίδιον εἰς τὸ φρέαρ ῥῖψαι καὶ ὑφ᾿ ἡδονῆς ἐλθεῖν εἰς Μακεδονίαν ἐπὶ τὸν Κασάνδρου γάμον.
Ἐλέγοντο δὲ αὐτοῦ καὶ αἱ Πλάτωνος ἀκούειν μαθήτριαι, Λασθένειά τε ἡ Μαντινικὴ καὶ Ἀξιοθέα ἡ Φλιασία. ὅτε καὶ Διονύσιος πρὸς αὐτὸν γράφων τωθαστικῶς φησι· “καὶ ἐκ τῆς Ἀρκαδικῆς σου μαθητρίας ἔστι καταμαθεῖν τὴν σοφίαν. καὶ Πλάτων μὲν ἀτελεῖς φόρων τοὺς παρ᾿ αὐτὸν φοιτῶντας ἐποίει· σὺ δὲ δασμολογεῖς καὶ παρ᾿ ἑκόντων καὶ ἀκόντων λαμβάνεις.”