SCIENTIST’S DISCOVERS

Evening Star, Issue 21934, 22 January 1935, Page 10

SCIENTIST’S DISCOVERS

RAYS STEM GROWTH WASHINGTON, December 28. The discovery of two now rays from the sun which make plants bend toward the light was announced to-day by the Smithsonian Institution. These light rays, one blue and the other blue-green, have the mysterious power of rendering inactive the growthstimulating substance of plants, sometimes known as “ auxin,” by stopping growth on one side of a plant’s stem. These rays and some others cause the plants to bend. . If certain conditions should change, it is conceivable that the rays might make life on earth impossible by stopping all plant growth. Tho discovery, says the Smithsonian Institution, is of extreme importance in the whole scheme of things, since the life of the animal world (including man) depends upon plant growth. it is the work of Dr Earl S. Johnston, of the institution’s division of radiation and organisms. The rays probably stunt growth by breaking up tiie atoms of the growthstimulating substance, Dr Johnston believes.