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 the usual formation of the body. 
Among 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 
unknown 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. Ina 
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 
VOL. I. N 
