30 MARRIAGE AND HEREDITY 



one of his courtesans say to a puella : " Our lovers 

 care only for our beauty ; when that fades their fancy 

 passes to another. But with you it is different. Once 

 you meet with a lover who resembles you in disposi- 

 tion he becomes attached to you, and thenceforward 

 your happiness is assured." 



This brings us to the great saving clause in the 

 constitution of Eoman society — the growth of a third 

 form of marriage, called Usus, which was a contract 

 without any formal ceremony, or, in other words, 

 marriage by habit and repute. As a species of concu- 

 binage, terminable at the will of either party, Usus 

 seemed Kttle likely to exercise a beneficial influence, 

 and it did certainly produce great instability in the 

 marriage relation. There were women in Eome who 

 could reckon, to their credit or discredit, as many as 

 eight or ten past husbands, and St. Jerome tells us 

 of one being married to a twenty-third husband, who 

 had himself got rid of his twentieth wife. But like 

 that slight variation in the habits of a species which 

 in evolution leads to the most important metamor- 

 phoses, Usus was destined to revolutionise the morals 

 of the world. Latterly it became the general form of 

 marriage in Eome, and whatever its drawbacks may 

 have been, it possessed certain great and incontest- 



