Something analogous occurs in grafting; for Thouin found that three species of Robinia, which seeded freely on their own roots, and which could be grafted with no great difficulty on a fourth species, when thus grafted were rendered barren.

嫁接中会发生类似的事情； 因为 Thouin 发现三种刺槐，它们在自己的根上自由播种， 并且可以很容易地嫁接到第四种， 当这样嫁接时变得不育。