Note 15 — Chapter XVII · ON THE GOOD EFFECTS OF CROSSING, AND ON THE EVIL EFFECTS OF CLOSE INTERBREEDING.
Reading edition
Lord Somerville, ‘Facts on Sheep and Husbandry,’ p. 6. Mr. Spooner in ‘Journal of Royal Agricult. Soc. of England,’ vol. xx. part ii. See also an excellent paper on the same subject in ‘Gardener’s Chronicle,’ 1860, p. 321, by Mr. Charles Howard.