You can read about them here, in "Bridesmaids Revisited," by Susan Ryder, who tastefully avoids any reference to the recent film Bridesmaids. (Unlike me.) The text of the poem (in English) is there, too.
However, Merton's bridesmaids (aka virgins, but the word for "virgin" back then pretty much meant "young woman" or "maiden," and hence quite a bit of confusion ever after) do arrive at the wedding on motor-scooters, with burned-out motors, having run out of gas.
In Merton, these gals knew how to dance, so they were asked to stay!
Et voilà: il y avait
Cinq vièrges hurluberlues
Mais bien engagées
Dans le mouvement.
You've got to have bridesmaids at a wedding! Especially hurluberlues ones--"foolish" or "scatterbrained."
If it must be known, I am 1) not a virgin 2) quite hurluberlue.