Darwin mentions a remarkable breed of cows called the nata or niata.
The animal has a very short and broad forehead, with the nasal end
turned up, and the upper lip much drawn back. Its lower jaw projects
below the upper, and has a corresponding upward curve; hence its teeth
are always exposed. Its nostrils are seated high up, and are very open;
and the eyes are projecting. When walking, it carries its head low on a
short neck; and its hind-legs are rather longer compared with the front
ones than is usual.
The breed is supposed to have originated amongst the Indians southward
of the La Plata. It is fiercer than common cattle; and the cow easily
deserts her first calf if molested or visited too often. Now, it is a
singular fact that an almost similar structure to the abnormal one of
the niata breed characterises the great extinct ruminant of India--the
sivatherium. The breed is very true, and the niata bull and cow
invariably produce niata calves. "Can it be that this animal is an
aboriginal of the continent, and existed ages before the European breeds
were introduced?" asks Mr Darwin.