junit-oneclass target questions

[Daniel John Debrunner]

Q1) The junit-oneclass target has a classpath entry:
      <classpath>
        <pathelement path="${out.dir}"/>
        <pathelement path="${junit}"/>
      </classpath>
   However if execute a target such as junit-jdbc4 target without 
CLASSPATH set I fail to execute the task. When I explictly set CLASSPATH 
to just contain the classes folder and junit.jar from tools/java I run 
the task successfully.
So what is the above classpath entry doing?

Q2) From a call to junit-oneclass can I set a system property for the 
forked JVM? E.g.

    <antcall target="junit-oneclass">
      <param name="derby.junit.jvm"
             value="${jdk16}/bin/java"/>
      <param name="derby.junit.testname"

value="org.apache.derbyTesting.functionTests.tests.jdbcapi.AutoloadBooting"/>
    </antcall>

How could I set a system property that will be passed onto the JVM 
running the junit test?

Thanks,
Dan.