Mammalian hair is composed of a protein, keratin. It is the same protein that makes horn, fingernails, claws, skin epithelium, and dander.
Mammalian hair consists of three distinct morphological units, the cuticle, the cortex and the medulla. The distinctive pattern shown by these
units varies over the length of the hair in a way that can be very characteristic. The patterns exhibited by these units
in any given hair are often sufficient to identify the genus, the species, or even the individual that the hair came from.
Significance in the Environment:
Dog hair is highly variable.
References with Photographs and/or Drawings
Hausman, Leon Augustus, "Structural charactreistics of the hair of mammals", THE AMERICAN NATURALIST, vol. 54, no. 635, pp.496-523,
Hausman, Leon Augustus, "Recent studies of hair structure relationships", THE SCIENTIFIC MONTHLY, pp. 258-277,
Glaister, John, A STUDY OF HAIRS AND WOOLS, Misr Press, Cairo, 1931.
FBI site for Animal Hair Identification: http://www.fbi.gov/hq/lab/fsc/backissu/july2004/research/2004_03_research02.htm
Mayer, William V., "The hair of California mammals with keys to the dorsal guard hairs of California mammals", THE AMERICAN MIDLAND NATURALIST,
vol. 48, no. 2, pp. 480-512, 1952.
Stains, Howard J., "Field key to guard hair of middle western furbearers", JOURNAL OF WILDLIFE MANAGEMENT, vol. 22, no.1, pp. 95-97, January, 1958.
Mathiak, Harold A., "A key to hairs of the mammals of southern Michigan", JOURNAL OF WILDLIFE MANAGEMENT, vol. 2, no. 4, pp. 251-268, October, 1938.