Many authors, for example, Settegast, Pusch, Kašpárek, Kraemer and Rostafinski, have attempted to draw conclusions concerning age, quality and breed of cattle from the type of hair produced. Exact investigations of the length and other features of the hair are, however, rare in the literature. Bilek has recently made some investigations of this kind under the direction of Professor Kašpárek, and has estimated the relation between the medulla and the fibrous layer, and has shown that the cross section of the hair is sometimes circular and at other times elliptical in shape.