Cross-fertilisation is just as necessary for continued fertility of ideas as for that of organic life, and the attempt to frown this or that down merely on the ground that it involves contradiction in terms, without at the same time showing that the contradiction is on a larger scale than healthy thought can stomach, argues either small sense or small sincerity on the part of those who make it.
"Luck or Cunning?"
Samuel Butler
Cross fertilisation has made stronger individuals and types, and likewise it has maintained them.
"The Kempton-Wace Letters"
Jack London Anna Strunsky
Side Sections 216 Cross-fertilisation of the Rattlesnake-Plantain.
"My Studio Neighbors"
William Hamilton Gibson