Iridology is the study of the iris of the eye. Iri and Iris come from the Greek name of the goddess of the rainbow, Iris. The Greeks named the colored part of the eye after such a goddess because they noticed eyes come in many colors. However, most iridologists agree that there are only two colors of eyes--blue and brown. Brown eyes are traced back to more temperate regions near the equator while historically blue eyes originate from colder regions. Green eyes are the result of mixed races. Iridologists also claim that if a person ate only pure foods and cleared the surrounding of pollutants, the eyes would become more blue.

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Historically, the major function of the horse has been in assisting civilizations to conquer land and to expand in size. Because of the animal's incontestable strength and speed, horses have been useful tools on the battlefield. Even before humans could ride horses, they were used in wars to pull chariots. Furthermore, as horses were used more and more on the battlefield, the animals became a symbol of power and a status symbol of the upper class.

Horses also played a great role in the civilization of the western hemisphere. IN the sixteenth century, Spanish conquistadors introduced the horse into the Americas. Evidence shows that horses were pivotal in the settlement of the new world. Civilizations that did not have horses were more likely to remain undeveloped and isolated.

An inference in the passage above is that: