What can you describe the relationship between the doctor's race and Kino's race?

The doctor was of a race which dominated Kino's race,

"This doctor was not of his people. This doctor

was of a race which for nearly four hundred years had beaten and

starved and robbed and despised Kino's race, and frightened it too, so

that the indigene came humbly to the door,,,"

The doctor hence considered Kino with contempt and superiority. Kino really had nothing to compel the doctor to help his child.