weird echo behaviour...

[Alfred M. Szmidt]

Could someone explain the following behaviour for me?  Because I sure
do not understand it.

address@hidden:/tmp/foo$ touch 1 2 3 4 5
address@hidden:/tmp/foo$ foo=`ls`
address@hidden:/tmp/foo$ /bin/echo $foo
1 2 3 4 5
address@hidden:/tmp/foo$ /bin/echo "$foo"
1
2
3
4
5
address@hidden:/tmp/foo$ foo='1 2 3 4 5'
address@hidden:/tmp/foo$ /bin/echo $foo
1 2 3 4 5
address@hidden:/tmp/foo$ /bin/echo "$foo"
1 2 3 4 5
address@hidden:/tmp/foo$ /bin/echo --version
echo (GNU coreutils) 5.2.1