The dimorphism of cerumen was first discovered by Kishi in 1907. There are two types of cerumen which differ in colour and consistency: the flocky and gray dry cerumen and the sticky yellow to brown wet cerumen. The comprehensive review of the frequency of the different cerumen types and their geographical distribution result in evidence for the dry type as a distinguishing feature of the mongoloid peoples (including the American Indians). The frequency of the wet cerumen prevails significantly in the Negroid (Congoid) and the Europoid (Caucasoid) population. Intermediate incidence data are due to racial intermixture.