Fat-soluble E, found in green leaves, the germs of seeds, in olives and olive oil. and in other foods (lettuce is rich in it), is supposed to energize and potentize the reproductive glands. Many forms of E are said to exist in foods. It seems to be essential to reproduction in rats in which its absence causes the germ cells to perish and the seminiferous tubules, in which the germ cells are produced, to atrophy. The ovaries of the female remain normal but the fetus dies a few days after fertilization. No evidence of the need of this vitamin by man has been produced.

The alphabet has not been exhausted. There are a few other vitamins about which little or nothing is known. No doubt others will be discovered as the search continues. But brief space will be devoted to these other vitamins.

Vitamin J has not been shown to have any value to man. Von Euler reported in 1935 that he had succeeded in extracting from fruit juices a factor that has no effect in preventing scurvy, but that protects guinea pigs from pneumonia.

Vitamin K or the anti-hemorrhage vitamin (why not call it the blood coagulating vitamin?) is a fat-soluble vitamin that we are said not to require in our food as it is produced for us by the action of bacteria in the intestines. It is supposed to be essential to the coagulation of the blood.

Factors L1 and L2 are substances said to be essential to milk production. L1 is obtained from beef liver and L2 from baker's yeast, neither of which is ever eaten by most milk-producing animals. These two vitamins are thought to aid in maturing the milk-producing tissuse. If they are really essential vitamins, they are produced by plants and not by the liver of the cow. The cow only stores them in her liver.

Factor M: When it was found that niacin and combinations of this vitamin with B1 and B2 will not correct pellagra symptoms in Rhesus monkeys another vitamin was assumed. Dried brewer's yeast and liver extract are said to clear up these symptoms. Factor M is, therfore, assumed to exist. As dried brewer's yeast and liver extract are never eaten by monkeys in nature, Factor M must be present in the fruits and vegetables eaten by these animals, else Factor M is a fiction.

Factor U: This is a vitamin apparently essential to the growth of chicks. Its significance, if it has any, in human nutrition is unknown.

Factor W: Thought possibly to be related to Pyridine, is an additional growth-promoting factor needed by rats. Its relation to human nutrition, if it has any, is unknown.

Grass Juice Factor: In addition to the usual vitamins found in grass, the existence of a vitamin, or of other vitamins, in the juice of the grass is assumed, but its nature has not yet been established.