It is only by observing animals carefully, by noting accurately their good qualities and their faults, by watching the circumstances in which individuals are produced, raised, and kept, that we can account for what seems to us a sport or caprice of nature. We can then tell, first, how the same bull and cow have produced three calves with different properties; and, secondly, trace out the rules which we are to follow, to be almost uniformly successful in obtaining stock of the best quality. Experience shows that the qualities which are transmitted with most certainty depend on the most important organs of life; and so, in the forms of the viscera and the skeleton, variations are rare, not only in breeds of the same species, but in different species of the same genera. Moreover, in cases where the transmission of properties is so uncertain as to seem the result of caprice in nature, these properties are formed by superficial organs,--by the skin, the horns, the state of the hair, etc. But it is in qualities which are, in a measure, artificial, qualities produced by domestication, and often more injurious than useful to the health of animals, that variations most commonly occur. These change not only with the breed of one species, but with the different individuals of the same breed, of the same half-breed, and often of the same family. Bearing these elementary principles of natural history and physiology in mind, we shall comprehend how cows and bulls well marked in regard to escutcheons have produced stock which did not resemble them. M. Lefebvre Sainte Marie asserts that the influence of the escutcheons is very feeble in the act of reproduction. In this view, the escutcheon is almost nothing in itself. It depends on the state of the hair, on one of the most fleeting of peculiarities, on that which is least hereditary in animals. It has no value as a mark of good getters of stock, unless it is supported by marks superior to it from their stability,--a larger skeleton, double loins, a wide rump, highly-developed blood-vessels,--unless it is united with a spacious chest, round ribs, large lungs, and a strong constitution. The more complete the correspondence between these marks, the more the milking quality is connected with the general condition of the animal, the greater the chances of transmission; and when, with a view to breeding, we shall choose only animals having the two-fold character of general vigor of constitution and activity of the mammary system, and place the progeny under favorable circumstances, the qualities will rarely prove defective. Thus far the conclusions of Magne.