Fishing for reproductive subjects; selection; installation of the incubator; collecting the eggs; fecundation of the eggs by the sperm; the spawn is washed to extract all impurities; it is laid upon trays made of osiers; the sterile eggs are eliminated; the germ of the future trout appears after twenty-five days; for a month the young fry derive their nourishment from a small sac, called a vitellus, which appears on the under part of the body; the food of the young fish is composed of liver which is first grated and then passed through a sieve; the first meal of the fish after the disappearance of the vitellus; proportional size of the fish; after three months; six months; one year; two years; during all the stages of growth, the fish breeder is careful to separate the smaller sized fish from the larger, which would otherwise devour their weaker brethren; securing the full-sized fish for sale.
—The Film Index synopsis