The known facts suggested that the materials responsible for staining are present in the sap and are concentrated at the surface during drying. Results showed that sugars and other materials present in the fraction of high water solubility are the substances primarily responsible for staining. The information was used to relate sugar pine staining to the browing that occurs when foods are dehydrated. Such nonenzymatic browning is known to be caused by furan derivitives, which are primary degradation products of sugars. Stain-retardant chemicals showed little promise when used as simple dip treatments. It was concluded that the best means of controlling brown stain at the present time is to secure better coordination between cutting and processing operations, and to use moderate kiln-drying schedules.