Fish intelligence in paradise fish ("Macropodus opercularis") which avoid places where they have experienced a single attack by a predator and continue to avoid for many months. A number of studies have shown that fish can retain information for months or years. Anecdotally, channel catfish ("Ictalurus punctatus") can remember the human voice call announcing food five years after last hearing that call. Goldfish remember the colour of a tube dispensing food one year after the last tube presentation. Sockeye salmon still react to a light signal that precedes food arrival up to eight months since the last reinforcement. Some common rudd and
What Is a Nation? French citizen has to have forgotten the massacre of Saint Bartholomew, or the massacre that took place in the South in the thirteenth century. While many nations, such as France, begin with a feudal regime such as a monarchy, others, such as the United States and Switzerland, are formed by acts of consensual aggregation. France and many others, however, survived their feudal roots while maintaining their identity. Renan inquires what is the organizing principle? It can't be race, because France is "Celt, Iberian, German...The most noble countries, England, France and Italy, are the ones where the blood is most mixed."