Sheep, Merino, their selection, [31].
——, two sub-breeds unintentionally produced, [36].
——, mountain, varieties of, [76].
Shells, colours of, [132].
——, littoral, seldom embedded, [288].
——, fresh-water, dispersal of, [385]
—— of Madeira, [391].
——, land, distribution of, [397].
Silene, fertility of crosses, [257].
Silliman, Prof., on blind rat, [137].