According to Baines, indents (as a contemporary convention of signaling paragraphs) derive from the omission of the pilcrow.
Gill uses pilcrow in his Essay on Typography to signal paragraphs throughout the book, but sometimes he uses pilcrows in conjunction with the line break (thus pilcrow is always at the beginning of the line) and sometimes, Gill uses pilcrows without the line breaks i.e. wherever the paragraph happens to end in a given line.
My question would be: is there the difference between the two? Were line breaks practiced in scribal times? Any good resources on the evolution of pilcrow (other than the wiki article)?