This instinct, it must be admitted, is far from infallible, and, as has been hundreds of times remarked by naturalists, it is in many cases not an original faculty but an acquired and transmitted habit. It is a fact familiar to persons engaged in sheep husbandry in New England--and I have seen it confirmed by personal observation--that sheep bred where the common laurel, as it is called, Kalmia angustifolia, abounds, almost always avoid browsing upon the leaves of that plant, while those brought from districts where laurel is unknown, and turned into pastures where it grows, very often feed upon it and are poisoned by it. A curious acquired and hereditary instinct, of a different character, may not improperly be noticed here. I refer to that by which horses bred in provinces where quicksands are common avoid their dangers or extricate themsleves from them. See Bremontier, Memoire sur les Dunes, Annales des Ponts et Chaussees, 1833; premier semestre, pp. 155-157. It is commonly said in New England, and I believe with reason, that the crows of this generation are wiser than their ancestors. Scarecrows which were effectual fifty yeara ago are no longer respected by the plunderers of the cornfield, and new terrors must from time to time be invented for its protection. Schroeder van der Kolk, in Het Verschil tusschen den Psychischen, Aanleg van het Dier en van den Mensch, cites many interesting facts respecting instincts lost, or newly developed and become hereditary, in the lower animals, and he quotes Aristotle and Pliny as evidence that the common quadrupeds and fowls of our fields and our poultry yards were much less perfectly domesticated in their times than long, long ages of servitude have now made them. Among other inntances of obliterated instincts, this author states that in Holland, where, for centuries, the young of the cow has been usually taken from the dam at birth and fed by hand, calves, even if left with the mother, make no attempt to suck; while in England, where calves are not weaned until several weeks old, they resort to the udder as naturally as the young of wild quadrupeds.-Ziel en Ligchaam, p. 128. n.