STOLEN BRAINS by CAPTAIN S. P. MEEK Dr. Bird, Scientific Sleuth Extraordinary, Goes After a Sinister Stealer of Brains. THE INVISIBLE DEATH by VICTOR ROUSSEAU With Night-Rays and Darkness-Antidote America Strikes Back, at the Terrific and Destructive Invisible Empire. (A Complete Novelette.) PRISONERS ON THE ELECTRON by ROBERT H. LEITFRED Fate Throws Two Young Earthians into Desperate Conflict with the Primeval Monsters of an Electron's Savage Jungles. JETTA OF THE LOWLANDS by RAY CUMMINGS Into Remote Lowlands, in an Invisible Flyer, Go Grant and Jetta—Prisoners of a Scientific Depth Bandit. (Part Two of a Three-Part Novel.) AN EXTRA MAN by JACKSON GEE Sealed and Vigilantly Guarded Was "Drayle's Invention, 1932"—for It Was a Scientific Achievement Beyond Which Man Dared Not Go.