Abstract
Progress has been made in the search for the cause of the common cold. At present the most prominent viruses associated with common colds in adults and children are the rhinoviruses, but it is evident that several groups of viruses are involved. A three year survey conducted in Chicago indicates that rhinoviruses are responsible for 15 to 25 per cent of all common colds in young adults and are a major etiologic factor during the fall and spring. The rhinoviruses isolated in this study and those isolated by other workers belong to many different serologic types.