188 Vitamins in Human Nutrition
mature blood corpuscles in rats, associated with one of the
vitamin G factors, appears to have been pinned to ribo-
flavine, and there is a possibility of riboflavine scarcity being
concerned with such conditions as “aplastic anemia” in
man. A very remarkable fact about riboflavine in rats has
been brought to light by the observations of Professor
Szent-Gyorgyi that over a period of five years lousiness
appeared exclusively in rats on riboflavine-deficient diets.
When these lousy rats were fed riboflavine they promptly
lost their lice, and diseased patches of skin developed new
fur. This leads one to speculate as to whether Russian and
Polish peasants lack sufficient riboflavine, and whether if it
were rationed out to soldiers in war time it would help to
control such louse-borne diseases as typhus and relapsing
fever. Within the present year speculation as to this pos-
sibility has received support from an unsuspected angle.
Experimenters at Harvard have found that lack of ribo-
flavine renders rats highly susceptible to typhus.
We still have little accurate knowledge of the extent to
which animals other than rats are dependent upon ribo-
flavine in their food, but it is not likely that any higher ani-
mals can manufacture it. It is present in the flesh, liver,
kidneys, and heart, and to a less extent in other organs of
various animals, but whether some animals may be able
to make their own or have it made by micro-organisms in
their alimentary canals without importing it with the food
is uncertain. Chicks are known to need it in the food, and
recently it has been discovered that dogs provided with all
known or suspected vitamins except riboflavine become
yellow-livered and die. A dog in a state of utter collapse,
apparently staring death in the face, can be returned to
health within a few hours by injection of a few milligrams
of riboflavine. It is likely, therefore, that the need for