=Age Incidence.=--Scurvy may occur at any age if the diet does not furnish sufficient antiscorbutic factors. As a matter of fact, it is encountered most often among infants and adults, not because these two age-groups are particularly susceptible, but because there are peculiar attendant circumstances. In the case of the infant, it is due to the fact that for almost the entire first year of its life it is dependent entirely upon milk, a foodstuff poor in antiscorbutic vitamine, and containing, under favorable conditions, barely enough to meet its requirement. If, therefore, the potency of the milk is weakened, or if an insufficient quantity is fed, and more particularly when both of these factors are involved, a scorbutic condition will ensue. The reason why older children, those over one and a half or two years of age, do not develop scurvy is largely due to their varied and liberal diet, which is amply provided by the mother or guardian, so that even in times of want they receive more than their due share of the available food supply.[17] [17] It would seem, however, that the growing infant requires relatively more antiscorbutic vitamine than does the adult. We know that its caloric requirement is fully a quarter to a third greater. In regard to vitamine, judgment cannot be based on experimental evidence, but on comparative figures. For example, unless we take this viewpoint, we must believe that, as an infant of six months weighing 15 pounds requires 15 c.c. of orange juice daily to furnish its antiscorbutic quota, an adult weighing 160 pounds requires 180 c.c. daily--the juice of three good-sized oranges. On this basis the adult would require six quarts (6000 c.c.) of fresh milk daily, twelve times the minimum requirement for an infant, which is one pint (500 c.c.) a day. These figures are manifestly too high.