Statutes on the number of citizens depend greatly on circumstances. There are countries where nature has done everything ; thus the legislator has nothing to do. Why encourage people with laws to propagate, when the fertility of the climate yields enough people ? Sometimes the climate is more favorable than the terrain ; people proliferate, and famines destroy them ; China finds itself in this situation : hence a father sells his daughters and exposes his children. In Tonkin  the same causes bring about the same effects, and for that there is no need to go seek the opinion of metempsychosis, like the Arab travelers we are told about by Renaudot. 
For the same reasons, on the island of Formosa  religion does not allow women to bear children until they are thirty-five years of age ; earlier than that, the priestess bruises their womb and makes them abort.