232 



The JoiRXAL OF IIkreditv 



slightly different view, pointing out 

 that farmers finally get a glimpse of the 

 fact that their animals are getting to be 

 altogether too similar. Sexual differen- 

 tiation gives place to a sort of neutrality, 

 which may finally lead to sterility. 

 Magne admits that it is very difficult to 

 decide whether there is an actual power 

 for evil in inbreeding as such, or whether 

 any damage is wholly due to the union 

 of two strains of weakness or the inheri- 

 tance of a double dose of tendency to 

 some disease. In practice, however, he 

 advocates jjroceeding on the assumption 

 that inbreeding does lead directly to 

 injurv. Cornevin alone, the most 

 important of all, looks on inbreeding 

 somewhat more leniently. And as he 

 bases his views on a lot of first-hand 

 observations, I will consider his views 

 in a little more detail. 



THE DEFINITIONS OF CORNEVIN. 



Cornevin vigorously demands a dis- 

 tinction between the different grades of 

 consanguinity. It makes a great deal 

 of difference, he declares, whether one 

 makes a "direct" pairing, "for 

 example, father or grandfather, with 

 daughter or granddaughter" or a "col- 

 lateral" pairing (for example, uncle and 

 niece). If inbreeding is held in so little 

 esteem, it is because hasty generaliza- 

 tion from single instances has been 

 allowed to throw blame on all forms. 

 The results of lateral pairing can not, in 

 general, be com|)ared with those of 

 direct mating. Well, both now and in 

 the past we have been accustomed to 

 make the same distinction; only we 

 were accustomed to speak more gener- 

 ally merely of "closer" or "wider" 

 inbreeding; and today we have a meas- 

 ure for it, as has already been said, in 

 the line of ancestors, or free generations. 

 The plausibility of Comevin's view can 

 be proved by actual experimental 

 breeding. 



Next he alludes to the closeness and 

 frequency of consanguineous marriages 

 in antiquity, pointing out that these 

 have not been wholly injurious. But 

 against such a conclusion, drawn from 

 human society, innumerable examples 

 may be quoted, particularly where inces- 

 tuous marriages were considered allow- 



able. The Veddas of Ceylon, among 

 whom marriage between brother and 

 sister is said to be the nile, are really 

 incapable of civilization, and also physi- 

 cally degenerate. As for the ancient 

 Greeks, it is true that they permitted 

 consanguineous marriages of very close 

 degree, but we have no evidence as to 

 the frequency of such unions with them. 

 But after all: the results of close in- 

 breeding often show themselves only 

 after it has been continued a long time. 

 Experiments in human society can cer- 

 tainly be quoted to throw light on the 

 question of inbreeding, but not in the 

 sense Cornevin tmderstands. 



HIS EXPERIMENTS. 



Cornevin made limited experiments 

 in inbreeding his own cattle, sheep and 

 swine very closely. His Hollanders were 

 inbred for 12, his Jerseys for seven years 

 in this manner, without showing any 

 e\'il results, and the prizes which the 

 animals won each year at district shows 

 certainly indicate that they did not 

 present evidence of degeneracy. The 

 Merinos Chdtillonais had been inbred 

 for 11 years at the time that Cornevin 

 wrote his Traite de Zootechnie generate 

 (1891) and were as little degenerated as 

 the cattle. On the other hand, this 

 ardent defender of inbreeding admits 

 that it can not be practised with York- 

 shire and Essex swine for more than two 

 or three generations. These animals 

 have such an inclination to lay on fat, 

 that it leads to sterility and lack of milk 

 on the part of the sows, when their 

 tendency is accentuated by line-breed- 

 ing. Indeed, adds Cornevin, the mere 

 necessity of keeping them in a j^en and 

 feeding them highly became hannful, 

 and it is questionable whether the result 

 would not have been very different 

 under more favorable circumstances. 



Pigeons regularly multiply adelpho- 

 gamically — that is, brother mates \\4th 

 sister; and so do swans, geese, guinea- 

 fowl and ducks very often, according to 

 Cornevin. He pursued inbreeding for 

 11 years with pigeons and geese, and 

 there was no perceptible change of color, 

 weight or fecundity. Guinea-fowls also 

 showed no change, but Houdans and 

 Crevecoeurs suddenly developed a strong 



