A true love story

Symbiosis (from Ancient Greek sýn "with" and bí?sis "living") is close and often long-term interactions between different biological species.
In 1877 Bennett used the word symbiosis (which previously had been used of people living together in community) to describe the mutualistic relationship in lichens. In 1879 by the German mycologist Heinrich Anton de Bary, defined it as "the living together of unlike organisms."

I wonder why these sound so familiar...

Mysteries explained in LARGE.