frontal bone, and then take a beautiful spiral form; in the ewes
they protrude nearly at right angles from the head, and then become twisted
in a singular manner."[225] Mr. Hodgson states that the extraordinarily
arched nose or chaffron, which is so highly developed in several foreign
breeds, is characteristic of the ram alone, and apparently is the result of
domestication.[226] I hear from Mr. Blyth that the accumulation of fat in
the fat-tailed sheep of the plains of India is greater in the male than in
the female; and Fitzinger[227] remarks that the mane in the African maned
race is far more developed in the ram than in the ewe.

Different races of sheep, like cattle, present constitutional differences.
Thus the improved breeds arrive at maturity at an early age, as has been
well shown by Mr. Simonds through their early average period of dentition.
The several races have become adapted to different kinds of pasture and
climate: for instance, no one can rear Leicester sheep on mountainous
regions, where Cheviots flourish. As Youatt has remarked, "in all the
different districts of Great Britain we find various breeds of sheep
beautifully adapted to the locality which they occupy. No one knows their
origin; they are indigenous to the soil, climate, pasturage, and the
locality on which they graze; they seem to have been formed for it and by
it."[228] Marshall relates[229] that a flock of heavy Lincolnshire and
light Norfolk sheep which had been bred together in a large sheep-walk,
part of which was low, rich, and moist, and another part high and dry, with
benty grass, when turned out, regularly separated from each other; the
heavy sheep drawing off to the rich soil, and the lighter sheep to their
own soil; so that "whilst there was plenty of grass the two breeds kept
themselves as distinct as rooks and pigeons." Numerous sheep from various
parts of the world have been brought during a long course of years to the
Zoological Gardens of London; but as Youatt, who attended the animals as a
{97} veterinary surgeon, remarks, "few or none die of the rot, but they are
phthisical; not one of them from a torrid climate lasts out the second
year, and when they die their lungs are tuberculated."[230] Even in certain
parts of England it has been found impossible to keep certain breeds of
sheep; thus on a farm on the banks of the Ouse, the Leicester sheep were so
rapidly destroyed by pleuritis[231] that the owner could not keep them; the