. Effects of the rays of radium on plants . Fig. 21. Activity of Radium, 1,800,000. April 17, II A. M. The exposed seeds, together with eight control seeds, were planted in soil, in similar pots. April 21, 2 P. M. No marked difference could be observed in the six cultures. No measurements were taken. April 23, 10 : 30 A. M. Average lengths of the hypocotyls above the surface of the soil: 14 hrs. 6 hrs. 4 hrs. 3 hrs. 2 hrs. Control mm. mm. mm. mm. mm. mm.

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Keywords: ., bookcentury1900, bookdecade1900, bookpublisher, booksubjectplants