help: composition & aggregation etc static non-static error message

From: javac (javac_at_mail.com)
Date: 03/29/04 

Date: 29 Mar 2004 11:44:18 -0800

to learn java I'm working on an eco-system simulation, the source's at:
http://www.geocities.com/cjavacjava/src/

class XYZcoordinates has three fields: int x,y,z

class Cat inherits from abstract class LifeForm

each cat needs one and only one XYZcoordinates object

I think I know what I want, but keep getting errors about
static/non-static references to static/non-static variables.

please do look at the code :)

javac@mail.com