O.K. I don't really doubt it, especially considering the source. My only point really was that Darwin peppered his correspondence with self effacing comments like these. Anyone who has read many of Darwin's letters is familiar with comments like them, BUT is also equally aware that they do not actually reflect a lack of confidence on Darwin's part concerning evolution. Darwin was trying to disarm his correspondents long enough to get a fair hearing for his ideas, to draw out pertinent criticism, or (most often) to wheedle others into providing data, answering questions, or helping with experiments. Darwin was a prodigious charmer and wheedler. It's astonishing the amount of work he got others to undertake on his behalf: everyone from other scientists, to professional gardeners to pigeon fanciers. Not to suggest that Darwin was not hard worker himself.