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.
Organs (i.e., organized combinations of the four basic tissue types) are composed of parenchyma supported by stroma. The stroma is the connective tissue and the associated blood vessels and nerves which pass through it.