Socrates and the Brothers Glaucom in the Republic

In books two through four Socrates lays out three controversial measures. Each of these elicits a wave of laughter, right? And the first two waves of laughter concern the abolition of private property and then the abolition of the family. In book five he moves on to the defective regimes thinking he's finished with his best regime. But polar markers objects via itemantis and says that Socrates needs to go into the whole thing about women and children being held in common.