If, therefore, a cross is effected with satisfactory results, it should be continued by resorting to pure-bred bulls, and not by the use of any grade bulls thus obtained; for, though a grade bull may be a very fine animal, it has been found that he does not transmit his good qualities with anything like the certainty of a pure-bred one. The more desirable qualities are united in the bull, the better; but the special reason for the use of a pure-bred male in crossing is not so much that the particular individual selected has these qualities most perfectly developed in himself; as that they are _hereditary in the breed_ to which he belongs. The moment the line is crossed, and the pedigree broken, uncertainty commences. Although the form of the grade bull may, in individual cases, be even superior to that of his pure-bred sire, yet there is less likelihood of his transmitting the qualities for which his breed is most noted; and when it is considered that during his life he may scatter his progeny over a considerable section of country, and thus affect the cattle of his whole neighborhood, attention to this becomes a matter of no small public importance. This principle, so far as its application to breeding for the shambles is concerned, seems to me to be sound, and fully established by long experience and practice. Perhaps it is equally so, also, in breeding for the dairy. But it may be well to consider whether there are not other rational modes of judgment in the selection of animals for breeding with this specific object in view. There is a difference of opinion with regard to the practical value of the system of classification and judgment of milch cows discovered and developed by Guénon: some being inclined to ridicule it, as absurd; others to adopt it implicitly, and follow it out in all its details; and others still--and among this class I generally find a very large number of the most sensible practical judges of stock--to admit that in the main it is correct, though they discredit the practicability of carrying it so far, and so minutely into detail, as its author did.