The second half of the 16th century was a period of ferment and anarchy, marked by the arrival of the Portuguese and the rise of some remarkable adventurers, one of whom, Hideyoshi, conquered Korea and apparently meditated the invasion of China.
Cuenot, in order to explain certain features in the hereditary transmission of coat colour in mice, postulated the hypothesis that the grey colour of the wild mouse (which is known to be a compound of black, chocolate and yellow pigments) may be due either to the interaction of a single ferment and three chromogens, or vice versa, to one chromogenic substance and three ferments.
In 1789 a ferment arises in Paris; it grows, spreads, and is expressed by a movement of peoples from west to east.
Another objection was that even if bacteria obtained access through the stomata, they could not penetrate the cell-walls bounding the intercellular spaces, but certain anaerobic forms are known to ferment cellulose, and others possess the power of penetrating the cell-walls of living cells, as the bacteria of Leguminosae first described by Marshall Ward in 1887, and confirmed by Miss Dawson in 1898.
In spite of the inquiry being only in its initial stages, there is already good evidence to believe that Cuenot's theory is correct, and that an albino is an individual whose skin lacks the power to secrete either the ferment or the chromogen.
The yeast-conidia, which bud off from the conidia or their resulting mycelium when sown in nutrient solutions, are developed in successive crops by budding exactly as in the yeast plant, but they cannot ferment sugar solutions.
The material is moistened with a solution of common salt and placed in very large heaps to ferment for some weeks.
Not only do albinoes thus carry the determinants for pattern, but it has been known for some time that they also carry gametically, but never visible somatically, the determinants for either the ferment or the chromogen for one or more colours.
Fibrinogen occurs in the blood plasma, and is changed by a ferment into fibrin, to which the clotting of blood is due.
By the rennet ferment caseinogen is converted into casein, a substance resembling caseinogen in being soluble in water, but differing in having an insoluble calcium salt.