Feature

Cavemen’s Idea of Magic Shown by Paintings

Nature Ramblings: Lovers of Open Fields

Sick Vegetables Described in New Publication

Swelling Marble Makes Trouble in Quarries

First Glances at New Books

Front Matter

X-Rays Can Speed up and Reverse Evolution

Treasure Unearthed from Maya Pyramid

Low Resistance in Cold Intrigues Engineers

Larger Families May Again Become Fashionable

Two Weeks’ Delay Precedes X-Ray Sterility in Mice

Yellow Fever Certificates Recommended for Tropics