The family of Common Ruminants form a natural group comprehending the
greatest number of Ruminants. The feature which distinguishes the
animals composing it, not only from the Camel family, but also from all
the other Ruminants, is the existence of two horns on the forehead of
the male, and sometimes on the female.
The structure of these horns presents various differences, and has
caused the division of this large and important family into three
tribes, namely, Ruminants with hairy and permanent horns, hollow-horned
Ruminants and Ruminants which shed their horns.