The physical conformation of a country may operate for good or for evil. Hill land is proverbially dry; it affords good " lair", and is so far conducive to health, but, generally speaking, it lacks fertility, and is not so sustaining as that in less elevated positions.

It offers, however, advantages which are of considerable importance to the growing animal. The pasterns acquire slope, elasticity is imparted to the paces, and action is developed. The feet, too, acquire strength, with ample size and good formation.

Hills, however, when too steep, affect brood-mares prejudicially in the latter stages of pregnancy, especially when they are fat and caused to gallop down them.

In these circumstances the foetus is forced violently forward, and the shock imparted to it may either occasion an unnatural presentation and render foaling difficult, or provoke abortion.