But in the human species, the manner of thinking, the character, the passions, the humor, the caprice, the idea of preserving beauty, the pain of child-bearing, and the fatigue of a too numerous family, obstruct propagation in a thousand different ways.
Baina giza espeziean, pentsaerak, jiteak, grinek, fantasiek, apetek, edertasuna iraunarazteko asmoak, haurdunaldiko trabek, familia ugariegia izateak, mila eratan nahasten dute ugaltzea.