The text's vocabulary consists of only 50 different words, the result of a bet between Seuss and Bennett Cerf (Dr. Seuss's publisher) that Seuss could not complete an entire book without exceeding that limit (after completing The Cat in the Hat with 236 words). The 50 words are as follows: a, am, and, anywhere, are, be, boat, box, car, could, dark, do, eat, eggs, fox, goat, good, green, ham, here, house, I, if, in, let, like, may, me, mouse, not, on, or, rain, Sam, say, see, so, thank, that, them, there, they, train, tree, try, will, with, would, you