226 PRINCIPLES OF STOCK-BREEDING. 



.misfortune of entailing the defect on their off- 

 spring.' " 1 



A case of cleft iris (which is the analogue of hare- 

 lip) is recorded by Mr. Sedgwick, who sums up the 

 details as follows : " The chief points of interest in 

 the case are 1. The transmission of the defect with- 

 out its being shared in by the mother ; 2. That, while 

 two of her three sons had the defect, her three daugh- 

 ters were free from it ; and, lastly, that the maternal 

 grandfather, the maternal grand-uncle, the maternal 

 uncle, and the son of this last named, all shared in the 

 defect, which shows that the inheritance in this case 

 extended to at least four generations." a 



According to Mr. Wilde, " In a family of thirteen, 

 in the county of Sligo, mute twins occurred twice, be- 

 ing the seventh and eighth births : in the former both 

 children were mute females ; in the latter, a male and 

 female, the boy not mute. Of the entire thirteen 

 births in that family, five were males, none of whom 

 presented any defect; and eight were females, of 

 whom seven were deaf and dumb ; the order of the 

 birth of the mutes being the third, fourth, fifth, 

 eighth, ninth, and eleventh." The same author 

 states that " the proportion of sexes of the deaf and 

 dumb in England and Wales, where one in 1,738 of 

 the inhabitants was affected, is 100 males to 82.9 fe- 

 males ; in Scotland, where one in 1,340 of the inhab- 



1 Edinburgh Medical and Surgical Journal, vol. iv., p. 252, 180S, as 

 quoted in British and Foreign Medico- Cldrurgical Review, July, 1S61, 

 p. 148, note. 



* British and Foreign Medico- Chirurgical Review, April, 1861, p. 

 249. 



