Feature

Shrunken Heads of Sloths Are Trophis of Expedition

Booklists of the A. A. A. S.

Front Matter

Leaders of Invention Tell What the World Needs Most

Sugar Plays Leading Part in Pneumonia Germ’s Activity

High Blood Pressure May Be Compensatory Reaction

[Photograph]: Voltmeter

Hand and Foot: Part II: “A Classic of Science”

Lonely Magnetic Poles May Change Ideas of Universe

Blood Examination Urged to Prevent Poisoning

In Science Fields

Fighting Radio’s Bugaboos