160 MARRIAGE AND HEREDITY ^ 



a larger skull and a more highly developed brain than 

 the Hottentot. The European child is born with a 

 greater capacity for knowledge than the little African. 

 It is even alleged by a French writer that the cranial 

 capacity of the modern Parisians, according to his 

 measurements of skulls, is thirty-five square centi- 

 metres greater than that of their ancestors of the 

 twelfth century.^ As a process of elevation goes on 

 in entire races, it is highly probable that within certain 

 limits the crossing of talent would be advantageous. 

 Without a rigorous adoption of the in-and-in system 

 of breeding, with its multiform dangers, we must be 

 prepared, however, to see all wide departures from 

 the general rule of development repressed by the 

 operation of natural laws. In heredity, tout se paye. 

 Nature appears to have a horror of exceptions, and 

 whether they occur in the direction of plus or minus, 

 she takes immediate steps to restore the equilibrium. 

 The mental peculiarities of an individual, whether good 

 or bad, are not traceable in his offspring beyond the 

 fourth or fifth generation. Every generation has its 

 inequalities, which Nature steadily counteracts by the 

 dual influence of the sexes. 



^ Broca, Memoire de la SocUt6 d' Anthropologic, 1873. 



