Questão sobre Genéricos

import java.util.*;

public class Organic<E>
{
	void react(E e) {}
	static void main(String []args)
	{
		//Organic<? extends Organic> compound= new Aliphatic<Organic>();
		Organic<? super Aliphatic> compound= new Aliphatic<Organic>();

		//compound.react(new Organic());
		compound.react(new Aliphatic());
		compound.react(new Hexane());
	}
}
class Aliphatic<F> extends Organic<F>{}
class Hexane<G> extends Aliphatic<G>{}