The Hair of California Mammals with Keys to the Dorsal Guard Hairs of California Mammals

摘要: It has long been recognized that hairs are as characteristic of mammals the glands which give class its name. When do not appear in adult animal, Odontoceti, they at least present embryo. They may be confined, Mysticeti, to region nares, or over entire body, Reindeer, even usually bare mammalian snout is hairy. In recognition this presence hair it was one time proposed should named Trichozoa Pilifera. recent years significant investigations on have few, latest contribution note being Hamilton et al. (1951). latter part nineteenth century and early twentieth more extensive research accomplished. However, merely 47 than 3000 references possession author deal primarily with a means classification identification, majority these anthropological studies human hair. Only 17 concern themselves wholly sizeable problem other man. With respect, then, systematic usefulness little done, taxonomic value subject all authors agreed. Cole (1924: 120) Nason (1948: 358), studying bats, both came conclusion use- identification. Mathiak (1938), Williams Brown (1942) arrived opposite conclusion, prepared aids for identifying certain basis alone. group complete agreement. The ability make positive identification great fields such criminology paleontology particularly field food habits studies. Fortunately relatively durable feature, high percentage shafts recovered from digestive tracts birds capable used purpose making HAIR STRUCTURE shaft highly keratinized column lacking nerves blood vessels. follicle formed embryologically an ectodermal invagination cells malpighian layer epidermis. This splits, proliferating base follicle, nourished by deeper-lying dermal papilla, move peripherally proper (Danforth, 1925: 23). As outward basal.bulb, become tend lose their individual identity. 480