The (almost really) Complete Works of Lewis Carroll

Puzzle

Source: sent to Mary, Ina, and Harriet or “Hartie” Watson, 1869

When .a.y and I.a told .a..ie they’d seen a
Small ..ea.u.e with .i..., dressed in crimson and blue,
.a..ie cried “’Twas a .ai.y! Why, I.a and .a.y,
I should have been happy if I had been you!”

Said .a.y “You wouldn’t.” Said I.a “You shouldn’t—
Since you can’t be us, and we couldn’t be you.
You are one, my dear .a..ie, but we are a .a..y,
And a.i...e.i. tells us that one isn’t two.”