Okay,
I will answer this question my own, since I now know my mistake in the try to install the old PHPUnit version by PEAR.
The Command for installing the old version 3.7.37, which I have at the old virtual machine, is
sudo pear install --force --alldeps phpunit/PHPUnit-3.7.27
Since this is the worst possible solution I have it would be nice to receive additional answers. By the end of this day I gonna accept the best.