Only the last fugue is written in two-step notation for keyboard instruments instead of four-step notation. The content is also designed for keyboard instruments, so it needs to be adjusted a little for ensemble use.
bar1-19 : A part, main Theme + counter Theme
bar19-24 : B part, counter Theme
bar24-35 : C part, main Theme
bar35-40 : D part, Interlude
bar40-53 : E part, inverse Theme, aug. Theme
http://aeolianconsort.chakin.com/Chausson.htm