Intermarriage, or, How and why beauty, health and intellect result from certain unions, and deformity, disease and insanity from others / by Alexander Walker.

  • Walker, Alexander
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: Intermarriage, or, How and why beauty, health and intellect result from certain unions, and deformity, disease and insanity from others / by Alexander Walker. Source: Wellcome Collection.

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    few who have the knowledge and the means to improve their families), the original combinations are perpetually reproduced* and the character of the original colonists or invaders is every- where to be seen, as in the counties now mentioned. In regard to the importance of this law as regards the crossing of the breeds of animals, the slightest consideration will show that, if, of the two great series of organs described, each belongs entirely to a distinct parent, we consequently can neither derive, in progeny, both series from one parent, nor portions of both from each parent, but that every attempt to do so must be a failure, and must consequently lead to mere loss of time and money.—It, at the same time, indicates the rational mode of procedure.—It moreover shows that, in a feeble or imperfect cross, bad as well as good combinations may be pro- duced ; but that such progeny as present the precise qualities desired must alone be employed in further breeding, while inferior progeny is cast aside. Here, it will be observed, that while great difference was sought for in the cross, similarity is sought for in the pair it produces, for, without that, there could be no homogeneity or conformity of breed—it would seem (to use Mr. Knight's language) to want permanence; nor can any cross ever be established without this similarity being obtained in its produce. This similarity has nothing to do with that quasi identity which is the principle of close and strict in-and-in breeding. Moreover, it is soon diversified by the modifications and accidents arising in an enlarging herd or flock, and permitting, according to the first law, the practice of that selection which maintauis the cross, without degenerating into in-and-in. III. Law of In-and-in Breeding, WHERE BOTH PARENTS ARE OF THE SAME FAMILY. The third law, namely that of in-and-in breeding, operates where both parents are not only of the same variety, but of the same family in its narrowest sense, and when the female gives