I think you don't understand the context. Cite the page number in Origin of Species so we can check it out.
And as natural selection works solely by and for the good of each being, all corporeal and mental endowments will tend to progress towards perfection.
http://www.literature.org/authors/darwin-charles/the-origin-of-species/chapter-14.html
He never cited this quote, but did for another one, which turned out to be taken completely out of context. In fact, the passage was making the complete opposite point Andy said he thought it did (I really think Andy is trying to fool people into believing creationist nonsense).