no 



The Journal of Heredity 



America. It is bcin^ emphasized on 

 both continents, however, by the de- 

 velopment of breeders' association and 

 herd and stud books, with the subse- 

 quent premium put on accurate regis- 

 tration. In Germany the development 

 of these instruments has proceeded on 

 much the same Hnes as in America, but 

 there has been more cooperation be- 

 tween the jjromoters of different breeds 

 — a cooperation largely brought about 

 by the huge and powerful German 

 Agricultural Society, whose 18,000 mem- 

 bers rc]jrcsent the advanced element in 

 scientific agriculture in the empire; and 

 largeh' directed by the German Genetic 

 Association, whose princijjal function is 

 the registration of pedigrees and their 

 subsequent study. It is chiefly as a 

 result of the work of the latter, Dr. 

 Wilsdorf says, that sentiment in Ger- 

 many has been changed on the subject 

 of Hne-breeding. The verdict of the 

 older school of zoologists had been 

 against it, but imjjartial examination of 

 horse pedigree charts by Lehndorft" and 

 others convinced them that much of the 

 progress made in the live-stock in- 

 dustry was due to line-breeding, and 

 they began to recommend it. Then the 

 value of a "genetic analysis" of each 

 animal came to be realized — that is, an 

 examination of its ancestry to determine 

 how it should be mated. A good 

 example of the way pedigree study can 

 be i)ut to use is his descrii)tion of the 

 work of the famous zootechni.st Dr. de 

 Chajjcaurouge at the national stud farm 

 in Celle. He brought together pedigrees 

 of many of the Hanoverian stallions 

 there and found that the stallion Nord- 

 ing got good colts in some districts, but 

 very poor ones in others. This fact had 

 been recognized by the Celle breeders, 

 but its cause was a com])lete mystery. 

 Testing theory by fact, de Chajjcaurouge 

 was able to prove that the good colts 

 were regularly produced when Wording 

 was mated to a mare with which he was 

 related. As the mares in his own 

 particular district were much more 

 likely to be related to him than were 

 marcs of more remote districts, the 

 result was that he had been getting 

 valuable colts in that district and com- 

 paratively worthless ones whenever he 



went out of it — a result that would have 

 remained a mystery, had it not been 

 demonstrated that the principle of 

 consanguineous breeding was sufficient 

 to cx])lain it. 



CONSANGUINITY WIDESPREAD. 



The amount of consanguinity among 

 the domesticated animals of any dis- 

 trict is, as Dr. Wilsdorf points out, 

 easily under-estimated. "Sui^pose we 

 take, as illustration, a valley in which 

 there are 50,000 head of stock of any 

 given kind. If this niimber of animals 

 had only parents, grandparents and 

 great-grandparents which were unre- 

 lated to each other, then we would 

 have — reckoning 14 ancestors for each 

 animal — 700,000 unrelated animals as 

 ancestors of these 50,000. If one tries 

 to find out whether such a condition 

 could actually exist in practice, and 

 examines the ])cdigree book of some 

 large herd, he finds the actual number 

 of ancestors is immensely smaller than 

 calculation led him to expect. The same 

 animal will appear over and over again 

 in the ancestry of a given indi\-idual, so 

 that most of the animals now living 

 trace back to numerous common an- 

 cestors. In the herd which we have 

 taken as an illustration, we would not 

 find 700,000 ancestors, but perhaps half 

 that many, or even less. 



"In our studies of the history of 

 various breeds, we next made the as- 

 tonishing discovery that the best living 

 individuals belonged to families which, 

 when their pedigrees were traced, were 

 found all to come from a single family — 

 often from a single individual. By way 

 of illustration I might cite the Hanover- 

 ian halfbloods, which we know particu- 

 larl\- through the studies of de Chapeau- 

 rouge and Grabensee to have come 

 almost altogether from three stallions, 

 of which Norfolk has hitherto had the 

 greatest influence on the breed — an 

 influence that is increasing all the time. 

 Researches into the swine breeding of 

 the Vis.selhovede district, and into that 

 of Hildesheim in Bavaria, have shown 

 that in each case a single boar was the 

 ancestor of various valual)le families, 

 today wielely scattered. And Heiesch 

 of Xeukirchen has found that his vain- 



