The species theory, polygenism, held that human races were of different lineages and suggested a hierarchy outlined in the Chain of Being that positioned Africans between man and lower primates.
No, they are involved in the Circulatory System which is responsible for pumping and channelling blood to and from the body and lungs with heart, blood and blood vessels. no veins are not considered an organ because they are a grouping of different tissues like a organ.
Definition of vein for English Language Learners : any one of the tubes that carry blood from parts of the body back to the heart : any one of the thin lines that can be seen on the surface of a leaf or on the wing of an insect