Shady Characters

“Punctuation itself – literally, the act of adding ‘points’ to a text – did not arrive until the third century BC, when Aristophanes of the great Library at Alexandria described a series of middle (·), low (.) and high points (˙) denoting short, medium and long pauses. Over the centuries, this system gave rise to punctuation as we know it: from Aristophanes’ three dots came the colon, the full stop, and many other marks besides. At the same time the paragraphos evolved into the ‘pilcrow,’ a C-shaped mark (¶) placed at the start of each new section in a text. The word space was a late arrival, appearing only when monks in medieval England and Ireland began splitting apart unfamiliar Latin texts to make them easier to read.”

"Maximal meaning in minimal space: the history of punctuation" - http://www.shadycharacters.co.uk/?p=279