An article in Science Times lauds The Wonders of Blood. This is another of the places in nature where networks are found set the laws of function. We are learning a lot from the roles of networks in life — for example in the networks we call ecologies. In the Science Times article we see that blood traverses a network, providing a way for our organs message each other:

Our blood is the foundation of our very existence as multicellular animals, said Andrew Schafer, a professor at Weill Cornell Medical College and the outgoing president of the American Society of Hematology. Blood is the one tissue that comes into contact with every other tissue of the body, and it is through blood that our disparate parts communicate, through blood that our organs cooperate. Without a circulatory system, there would be no internal civilization, no means of ensuring orderly devotion to the common cause that is us.

“It’s an enormous communications network,” Dr. Schafer said — the original cellphone system, if you will, 100 trillion users strong.