INHERITANCE OF MONSTROSITIES. 177 



itself in a specially striking manner in the case of certain 

 diseases, and in unusual and irregular (monstrous) devia- 

 tions from tlie usual formation of the body. 



Amono: these cases of the inheritance of monstrous devi- 

 ations, those are specially interesting which consist in an 

 abnormal increase or decrease of the number five in the fin- 

 gers or toes of man. It is not unfrequently observed in 

 families through several generations, that individuals have six 

 fingers on each hand, or six toes on each foot. Less frequent 

 is the number of four or seven fingers or toes. The unusual 

 formation arises at first from a single individual who, from 

 unkno^vn causes, is born with an excess of the usual number 

 of fingers and toes, and transmits these, by inheritance, to a 

 portion of his descendants. In one and the same family it 

 has happened that, throughout three, four, or more genera- 

 tions, individuals have possessed six fingers and toes. In a 

 Spanish family there were no less than forty individuals 

 distinguished by this excess. The transmission of the sixth 

 finger or toe is not permanent or enduring in all cases, be- 

 cause six-fingered people always intermarry again with 

 those possessing five fingers. If a six-fingered family were 

 to propagate by pure in-breeding, if six-fingered men were 

 always to marry six-fingered women, this characteristic 

 would become permanent, and a special six-fingered human 

 race would arise. But as six-fingered men usually marry 

 five-fingered women, and vice versd, their descendants for 

 the most part show a very mixed numerical relation, and 

 finally, after the course of some generations, revert again to 

 the normal number of five. Thus, for example, among eight 

 children of a six-fingered father and a five-fingered mother, 

 two children may have on both hands and feet six fingers 



