On The Origin of Species by Charles Darwin Chapter 1 Page 10

causes as to fail to act, we need not be surprised at this system, when it does act under confinement, acting irregularly, and producing offspring somewhat unlike their parents. I may add that as some organisms breed freely under the most unnatural conditions — for instance, rabbits and ferrets kept in hutches — showing that their reproductive organs are not easily affected; so will some animals and plants withstand domestication or cultivation, and vary very slightly — perhaps hardly more than in a state of nature.

Some naturalists have maintained that all variations are connected with the act of sexual reproduction; but this is certainly an error; for I have given in another work a long list of “sporting plants;” as they are called by gardeners; that is, of plants which have suddenly