Backquote Mystery

[Com MN PG P E B Consultant 3]

While hunting a bug in my script, I stumbled over an effect involving
the usage of
backquote and grep, which completely puzzles me. To reproduce the
effect, execute
first the following four commands, which create a small directory tree
in your 
working directory and set the bash variable 'e':

        mkdir -p dirx/sub/f
        cd dirx
        touch x
        e=$('ls' *)

Wenn you now do echo $e, you should get the following output:

        x sub: f

And here comes the mystery part. Execute the following two commands:

        echo g|grep "$e"
        echo g|grep "x sub: f"

Could some kind soul explain to me, why the first grep matches?

BTW, BASH_VERSION is "2.05b.0(1)-release"


Ronald