Contents

31 January 1964
Vol 143, Issue 3605

About The Cover

Aerial view of aromatic shrubs (Salvia leucophylla and Artemisia californica) invading an annual grassland. Happy Canyon (Santa Inez Valley, Santa Barbara County, California) is representative of vast areas where similar patterning has occurred after bio-chemical inhibition of herbs. White borders surrounding shrub zones are areas of maximum inhibition; the soil is almost devoid of herbs. See page 471.) [Jack Ward, Mark Hurd Aerial Surveys, Inc.]