This is an amusing exercise for beginning readers, especially those who are inadequately equipped to skim or guess at words and who need a gentle brake applied. The sentence length, word shape and sounds employed require reader alertness and word-by-word recognition. One example will serve to show this as a strength of the book -- "Clocks on fox tick. Clocks on Knox tock... Six sick bricks tick. Six sick chicks took." This same example also shows the weakness of many of these when considered purely as twisters. They can seldom survive a glance away from the Dr.'s characteristic, boldly colored drawings. Seen with the illustrations, however, they make for a certain kind of verbal/visual nonsense.