The Mad Doctor of Market Street

"You see I've gone as far as I can with my scientific research among the lower animals, but it is obvious that my findings will not be accepted by the medical world until they have first been demonstrated upon a human being."

"Genius — or fiend?"

"Lionel Atwill — Graham / Dr. Ralph Benson"

"Una Merkel — Aunt Margaret Wentworth"

"Claire Dodd — Patricia Wentworth"

"Nat Pendleton — Red Hogan"

"Anne Nagel — Mrs. William Saunders"

"Hardie Albright — William Saunders"

"Richard Davies — Jim"

"John Eldredge — Dwight, Ship's Officer"

"Ray Mala — Barab"

"Noble Johnson — Native Chief Elan"

"Rosina Galli — Tanao, the Chief's Wife"

"Al Kikume — Kalo"

"Milton Kibbee — Hadley"