Chapter 18 - Conclusion

The art of breeding fine dogs, like the other arts, is long. It requires a never-failing interest, a devotion to the ideal toward which one works, and a persistent study of the methods by which that ideal may be approximated.

A single book is only a stone cast into the still pond of the subject to set up an ever widening wave of inquiry which it may require a whole library to satisfy. This book is intended to be that stone. Included hereafter is a bibliography of a few of the books and articles which have seemed to the authors germane to the subject in hand and from which many of the data contained in these pages have been gleaned. It is hoped that the simple statements of the scientific facts herein set forth may stimulate the reader to a further exploration of the realm of genetics and to the practical application of that science to the improvement of the domestic dog. That quest of truth should not, in fact, end short of infinity. In the breeding of dogs there are always more worlds to conquer.

There are, no doubt, readers of this book who would prefer simply to be assured that their bitch Queenie or Lady is an ideal brood bitch of her variety and that if only Queenie should be bred to John Doe's dog Duke, a litter of champions would be certain to result. To offer such assurance, even if it were possible to do so, would deprive the breeder of the creative joy of his art and would make the breeding of his dogs simply another chore.

We have chosen, on the other hand, to seek to show how the breeder may himself consider the fitness of his stock and how he may himself mate that stock for its betterment.

That is not intended as an implication that the advice of experienced and successful breeders of dogs should be ignored in the making of specific mating , but that advice when asked and given should be critically considered in the light of scientific truth. The breeder who uncritically carries out the breeding scheme of another is not a creative artist at all. He is merely a chore boy who does the bidding of a more creative mind.

Even successful breeders may be the slaves of some or all of the superstitions which it is sought to explode in Chapter XIV, but they are successful despite that slavery rather than because of it. Men have bred fine dogs without ever having heard of a chromosome or a gene and in the belief that Mendelism is some kind of esoteric religious cult. These same men might have bred more fine dogs and better ones if they had had the scientific facts which genetics has supplied. The element of luck in the breeding of dogs has turned the scales sometimes toward excellence, more often away from it. The scientific breeder seeks to eliminate that element as far as may be and to substitute for it a sureness of procedure and a certainty of reward for his efforts.

This, the new science enables him in great part to do. The word "blood" to designate the vehicle of heredity is so firmly fixed in our vocabularies that it is difficult to discard in favor of the gene concept. The breeder who succeeds in substituting genes for blood in his deeper consciousness, who thinks of matching genes rather than of blending blood, has gone far in the resolution of his breeding problems. The knowledge that the picture he seeks to make is to be a mosaic of genes rather than a daubing of blood revolutionizes his breeding practice as well as his thought processes.

The science of genetics is only in its swaddling clothes and its practical application to plant and animal husbandry has hardly yet begun. The workers in its vineyards are pure scientists who have but little concern for the practical use of the truths they reveal. Since Aristotle, and before, men have speculated about heredity, what it was and how it behaved. Except for the revelations of Mendel, however (and those revelations lay dormant and unregarded for a third of a century), only in our time has any progress been made in the resolution of the mystery.

Painter at the University of Texas and Bridges, an associate of Morgan's at the California Institute of Technology, have seen fine bands on the chromosomes of the large cells of the salivary glands of Drosophila. These workers believe that these minute bands may actually be the hitherto unbeheld genes.

At the University of Indiana the sex of chickens is influenced by the piercing of the air chamber of the eggs from which they are hatched. This at first glance seems to nullify the theory of the X and Y chromosomes as the determiners of sex. It does not, in fact, do so for the sex chromosomes only predispose the zygote toward one sex or the other, but not irrevocably.

As we have previously noted, Soviet workers have succeeded in separating the Y-carrying sperm from the X-carrying sperm by centrifuging the semen.

The end is not yet. Data continue to pile up. The work gathers momentum. The ensuing years may bring us undreamed of knowledge and may enable us to accomplish more in the realm of practical breeding than now seems possible.

Much of the new knowledge appears not possible of practical application but each new fact leads forward to other facts and the work goes on with even greater acceleration. The wise breeder is interested in these new facts for their own sake and will not go ignorant of the developments of genetic science.

In 1934, Dr. G. G. Pincus, working at Harvard University, was able to produce rabbits by shaking together ova and sperm in a test tube and placing the fertilized ova in the Fallopian tubes of another rabbit for gestation. Later, Dr. Pincus was able to bring about the fertilization of the ova of rabbits by the use of heat and by soaking them in brine, subsequently transplanting them into the Fallopian tubes of an unrelated female, where pregnancy ensued. Except for the deities of some religions, this is the first recorded parthenogenesis of a mammal. Early in this century, Jacques Loeb had succeeded in activating the eggs of sea urchins with brine and the eggs of frogs by needle puncture, but Pincus' is the first success of the kind in the higher animals. The implications of such an achievement for the animal breeder and for the human race are so stupendous as to be well nigh imponderable.

The separation of the X-carrying from the Y-carrying sperm is not yet available to the practical breeder. We are not yet ready to breed Pomeranians by soaking Pomeranian ova in salt water and implanting a hundred of them in St. Bernard oviducts to produce vast, sireless litters. But what the future may bring forth is not unworthy of our speculation.

With the knowledge already at hand, we may so unite the chromosomes and the genes within them as to produce dogs more nearly to our hearts' desire.

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