Essential to the vitality of the skin is the blood supply. Textbooks insist that this is adequate in every way to meet the demands placed on it. The recent investigations of Petersen,1 Comel2 and Koenigstein3 substantiate my findings, which tend to cast considerable doubt on the statement. The cutaneous arteries supplying the hair papillae, Meissner corpuscles and papillary bodies are terminal vessels and have poor anastomotic connections, like those in the brain, kidneys and special sense organs. Furthermore the skin, as demonstrated by Krogh,4 has a relatively small potential capillary surface, so that, coupled with the circumstance that its vessels are terminal, it cannot respond adequately to a sudden and unusual demand for oxygen, which occurs, for instance, at times of increased activity. If to this is added anemia, when the blood cannot carry as much oxygen as it normally should, the