Here is the whole text of Darwin's Origin of Species. It has more than just dog breeding in it. Why argue with me, when you can look at the reasoning at its source?
Knock yourself out:
http://www.talkorigins.org/faqs/origin.html
Darwin didn't have a clue regarding the mechanism of inheritance. Why would I want to go back and re-read something that in light of today's science is a tad dated.