It will be admitted that the production of races so different as short-horn and Hereford cattle, race and cart horses, the several breeds of pigeons, etc., could never have been effected by the mere chance accumulation of similar variations during many successive generations.
Onartuko da betabere adarmotza eta Hereford-a, lasterketa-zaldia eta gurtzaldia, uso arraza diferenteak eta abarrak bezalako arraza hain ezberdinak sortzea, ezin izan dela sekula erdietsi hurrenez hurreneko belaunaldietan izaniko aldakuntzen metaketa hutsaz.