Looking at Galaxy NGC 891

Have a picture of this galaxy(I like pictures) This galaxy shows itself
as a parrel plane in our line of view(horizontal) The picture is shown
in visible light. The first thought that comes to mind looking at the
picture is "what is that very dark area?" This dark area seems to slice
the galaxy into an upper and lower parts. It looks like a long black
cloud blocking out the stars that are in back of it. Would all galaxies
have this feature when their line of view is edge on ?
Bert