Note 14 — Chapter XVI · CAUSES WHICH INTERFERE WITH THE FREE CROSSING OF VARIETIES—INFLUENCE OF DOMESTICATION ON FERTILITY.
Reading edition
Mr. Shirreff formerly thought (‘Gard. Chron.,’ 1858, p. 771) that the offspring from a cross between certain varieties of wheat became sterile in the fourth generation; but he now admits (‘Improvement of the Cereals,’ 1873) that this was an error.