176 PRINCIPLES OF STOCK-BREEDING. 



has written a very able thesis on the same subject, 

 which contains numerous observations on the influ- 

 ence of consanguinity on deaf -dumbness. It appears 

 that in the Deaf and Dumb Institution at Bordeaux, 

 of thirty-nine boys deaf and dumb, six were the off- 

 spring of such marriages ; and of these six, one boy 

 had two brothers deaf and dumb, and one boy had 

 three brothers deaf and dumb, making a total of 

 eleven. 



" Of twenty-seven girls, in the same institution, 

 nine were the issue of such marriages ; and of this 

 number, six had between them seven brothers and 

 sisters similarly affected, making a total of sixteen; 

 and very lately (1860), M. Devay, Professor of Clini- 

 cal Medicine at Lyons, has brought the same subject 

 before the notice of the Imperial Academy of Sciences, 

 in that city ; for, to so great an extent has the evil 

 prevailed, that in one of the departments of France 

 (Arieges), the clergy have endeavored to check the 

 frequency of such marriages, and have appealed to 

 the authorities at Montpellier to aid them in so do- 

 ing." 1 



" In a very able paper ' On Marriages of Consan- 

 guinity and Deaf -Dumbness,' which is generally sup- 

 posed to be one of the most constant defects resulting 

 from such marriages, M. Boudin informs us that ' deaf- 

 mutes are the issue of consanguineous marriages in the 

 proportion of twenty-eight per cent, at the Paris Im- 

 perial Institution, twenty-five per cent, at Lyons, and 



thirty per cent, at Bordeaux ; ' and that as regards the 

 < 



1 Sedgwick, in the British and Foreign Medico- Chirurgical Review, 

 July, 1861, p. 143. 



