PHYSICAL CHARACTERS IN MAN 97 



known.* This condition is rare. More or less complete 

 doubling of the extremities occurs in various mammals. 

 Cramer (1910) discusses cases of pol3^dactyly in man, 

 horses, a lamb, fowls, pigs, and a calf. Fackenheim 

 (1888) describes a family in which hereditary Poly- 

 dactyly is combined with tooth anomalies. The Heizler 

 family show^ed Polydactyly as a simple dominant in 

 four generations. A polydactylous man of the third 

 generation married a woman with tooth anomalies, 

 having two abnormally large, pointed teeth in place 

 of the incisors and only two cheek teeth. Of their 

 six children, three were normal and three showed 

 both abnormalities with some variations in the con- 

 dition of the teeth. 



A recent case of polydactylism in cattle is described 

 (Roberts, 1921). Many instances have been recorded. 

 In this one, from a herd of dairy cattle in Illinois, a 

 normal bull mated with a polydactylous cow, having 

 three toes on each foot, produced a polydactN'lous 

 female. She was mated to a normal unrelated bull 

 and produced three male calves, all polydactylous, 

 but one with a duplication of the metatarsal bones 

 of the hind feet, which bore four and five toes re- 

 spectively. The character is evidently' dominant in 

 inheritance. The third or extra toe is on the inside, 

 and probably represents digit II. It is alwa3^s 

 larger on the hind feet than on the fore feet. 



Bateson (1894, p. 376) describes a three-toed strain 

 of cattle from a three-tged cow bought in 1 861 . The 

 strain lasted until 1887, producing about ten genera- 



* The reference is in Suetonius, Bk. I., chap. Ixi. : " Utebatur 

 autem equo insigni, pedibus prope humanis et in inoduin digi- 

 torum unguUs fissis." ("He rode a remarkable horse too, with 

 feet that were almost human, for its hoofs were cloven in such a 

 way as to look like toes.") The writer goes on to say that it was 

 born in Caesar's stables, that he tended it with great care and was 

 the first to mount it, and that a statue of it was afterwards dedi- 

 cated in front of the temple of Venus Genetrix. 



7 



