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.
A blood cell, a liver cell, a skin cell, anything. So to answer your question, no. Organs are specialized for what they do, and are not made up of the same tissues. As you may already know, every part of your body is made of tissues, as tissues are defined as a group of cells performing similar or same functions. So not only is skin tissue, but semen and blood is as well. <br /><br /> Now, back to your question.