Now You've Done It

I'm reading a book called The Seeds Of Life by Edward Dolnick.  In a footnote that has little to do with the book's subject, he discuss the lyrics of Cole Porter.

He think the phrase "the birds and the bees" may have come from Cole Porter's "Let's Do It." The song famously opens with "Birds do it, bees do it, even educated fleas do it."

Except that wasn't the original opening.  As Dolnick notes, it was "Chinks do it, Japs do it, Up in Lapland even little Laps do it."

A few notes.

1)  There's no "even" before "little Laps."  It wouldn't scan.

2)  The "educated fleas do it" was originally in the song, but placed later.  In fact, it's still in a later chorus, making for an unfortunate repetition. (Except, because of a different number of syllables required, it's "even over-educated fleas do it." If the Lapland line that Dolnick mentions were moved down there, it would fit perfectly.)

3)  The rewrite was necessitated, as you can probably guess, by changing standards.  Dolnick either doesn't know, or doesn't have the time to note, how this change broke up the formal beauty of the song.  In the original, each chorus stuck to related items.  Thus chorus 1 is peoples of the world, chorus 2 are creatures of the sea, chorus 3 is insects and chorus 4 is mammals.