As vacation time approached, Dick and Doc had become as hard as nails and as active as a couple of manus, which you will know, if your education has not been neglected, is the ape-word for monkeys. Then it was that the big surprise came in a letter that Dick received from his mother. Tarzan of the Apes had invited them all to visit him and spend two months on his great African estate! The boys were so excited that they talked until three o'clock the next morning and flunked in all their classes that day.