This is considered one of the more desired of the 1930's card sets, not only for its adventurous subject matter and comic-strip-like artwork, but also because the cards are difficult to locate, especially in higher condition grades (owing to the thin card stock as well as advancing age).
The card fronts show a piece of color artwork surrounded by a white border, with the card number and a caption at the bottom. The card backs give the set title, repeat the number and card caption, and then a thick paragraph of text. At the bottom is the company information.
A similar card set was produced in Canada by the Canadian Chewing Gum Co. The text on the back of these was given in both English and French. One more difference is that the Canadian edition is on gray card stock while the American is on tan.
Note that the cards came not with gum, but in a product called Tarzan of the Apes Candy, in 1-cent packages.
Value: Cards from this set are difficult to accumulate. Individual cards in Excellent condition usually command around $20.00 each. A full set of 50 cards will probably cost between $1,000.00 and $1,200.00. Note that professionally graded cards will almost always command higher prices.
The American Card Catalog number for the American version of this set is R-147; the Canadian is V-256.