The Variation of Animals and Plants under DomesticationNote 4 — Chapter XVI · CAUSES WHICH INTERFERE WITH THE FREE CROSSING OF VARIETIES—INFLUENCE OF DOMESTICATION ON FERTILITY.Reading editionRengger, ‘Säugethiere von Paraguay,’ s. 336.◇Copy noteReturn to CHAPTER XVI. CAUSES WHICH INTERFERE WITH THE FREE CROSSING OF VARIETIES—INFLUENCE OF DOMESTICATION ON FERTILITY.