Imitation occurs when the following part follows the preceding one after a rest, preserving the same intervals by which the preceding part moved, without regard to mode, whole tone, or semitone. This can take place at the unison, second, third, fourth, fifth, sixth, seventh, and octave, as examples will make clearer.
Joseph. This last example seems to begin on C and end on G.
Aloysius. You have already forgotten what I said a little earlier: imitation is bound by no constraint of mode or tonal placement, and it is enough that the imitating part follows the footsteps of the preceding part in whatever manner. Moreover, imitation is customarily used less at the beginning of a composition than in its middle, where the strictness of the mode is not greatly attended to.
Aloysius. You will spend some time imitating these examples. Place a few notes at your discretion, copy them note for note into the other part at whatever interval you please, and, building above them with various note forms according to the precepts of counterpoint and with regard for graceful melody, you will construct a two-voice composition.