The American first edition used a punctuation mark (resembling an equals sign: '=') between sentences (after full stops, exclamation marks or question marks; in the earlier Egoist version it had been an m-dash).
In the initial American edition, sentences were separated by a punctuation mark resembling an equals sign (=) after full stops, exclamation points, or question marks.  The earlier Egoist version used an m-dash for this purpose.