He is talking about all organic beings descending from some primordial ancestor. This is most emphatically not simple micro-evolution with the mystical species-barrier required by creationists.
I am not trying to claim that I believe that Creationists, Evolutionists, or those that believe in ID are wholly right or wholly wrong. There are both extremists and moderates in all of these and the many other beliefs. I felt it important, however, to point out a part of Darwin's writing that many "Darwinists" choose to ignore, just as you pointed out a part that many evolution-acknowledging "Creationists" ignore. Since the original topic was churches celebrating Darwin's birthday, I thought I'd share an interesting book related on the topic. Perhaps I should have split my original post into two separate posts.
