52 PRINCIPLES OF STOCK-BREEDING. 



Another case is on record of the " hereditary ab- 

 sence of the two distal phalanges," in which " the 

 transmission of the defect for ten generations had 

 been effected by the females only of the family." 1 



A supernumerary organ, when inherited, may oc- 

 cupy a different position from that observed in the 

 parent, as in the case of a woman with three nipples, 

 published by Adrien de Jussieu. " The additional nip- 

 ple was placed in the groin, and served ordinarily for 

 suckling, while in the mother of this woman, who was 

 born also with three nipples, they were all placed on 

 the anterior region of the thorax." a 



The fifth toe of Dorking fowls, which is one of 

 the characteristics of the breed, has been inherited, it 

 is claimed, from a five-toed variety introduced into 

 Britain by the Romans. Whether this is true or not, 

 it is now impossible to determine, but the constancy 

 of this peculiarity, even in the produce of other breeds 

 crossed with the Dorking, would seem to indicate that 

 it is a character which has been fixed by long-con- 

 tinued inheritance. 3 



In the Houdan fowls, when first introduced into 

 England from France, a fifth toe was rarely seen ; but 

 at the present time it is nearly as constant in this 

 breed as in the Dorkings. 4 



Mr. "Wright says : " The abnormal structure of the 

 Dorking foot is very apt to run into still more abnor- 



1 British and Foreign Medico- Chirurgical Review, April, 1863, p. 460. 

 9 Ibid., July, 1863, p. 172. 



8 Wright on "Poultry," pp. 311, 312; Darwin's "Animals and 

 Plants under Domestication," vol. ii., p. 24. 

 4 Wright on " Poultry," p. 412, 



