Interbreeding and the Effects of Intercrossing

Many cases show how complex and unexpected are the checks and relations between organic beings which have to struggle together in the same country. I will give only a single instance which though a simple one interested me. In Staffordshire, on the estate of a relation where I had ample means of investigation, there was a large and extremely barren heath which had never been touched by the hand of man. But several hundred acres of exactly the same nature had been enclosed twenty-five years previously and planted with scotch fur. Not only the proportional numbers of the heath plants were wholly changed, but twelve species of plants flourished in the plantationswhich could not be found on the heath. The effect of