Answer:
The specific point in the text of "Fair Phyllis" where the voices imitate each other in rapid succession occurs in the following section:
"Fair Phyllis I saw sitting all alone,
Feeding her flock near to the mountain side.
The shepherds knew not,
They knew not whither she was gone,
But after her lover Amyntas hied,
Up and down he wandered,
Whilst she was missing.
When he found her,
O then they fell a-kissing."
In the lines, "Up and down he wandered, / Whilst she was missing. / When he found her, / O then they fell a-kissing," the voices imitate each other rapidly, echoing the actions of the characters in the narrative. This rapid imitation creates a sense of movement and excitement in the music, highlighting the joyful reunion of the characters.