Sheep-breeding

In the remarks on sheep-breeding which I am about to submit to you, I must beg you to understand that I do not profess to be able to offer you the results of any experiments of my own, nor any theory founded on the experiments of others.
I cannot find, indeed, that any experiments have ever been made upon any scientific principle, and upon such a scale as to arrive at any defined and certain laws, such as must underlie and govern the science of artificial selection, whilst on reference to those authorities who have written on the subject, I find discordancies of opinion, coupled with vagueness of technical phraseology, that must leave every one in doubt as to whether indeed we do know scientifically more of breeding now than we did one hundred years ago.