In the draft the song of the nightingale section
had a similar, companion section immediately following the section containing Mr. Eugenides' proposition. Lines from both sections were combined to produce the lines that were finally published.
203) Twit twit twit
204) Jug jug jug jug jug jug
205) So rudely forc'd.
In the draft both sections were composed of varying numbers of twits, jugs, Ters and Tereus. The phrase So rudely forc'd appeared in the first section and the phrase O swallow swallow appeared in the second section.
The O swallow swallow phrase appears again in the poem on line 428.
Citation: "The Facsimile" pp. 30-31