FIG. 15 



The maize plant was one of the earliest on which auximones were 

 tested. All the plants shown above were grown in sterilized sand 

 (washed silver sand). The plant on the right received nothing but 

 distilled water. The middle one received a complete chemical diet 

 (Detmer's). The one on the left received Detmer's +0*35 part per 

 million of the Silver fraction derived from the Phosphotungstic 

 precipitates obtained from bacterized peat. The photograph had 

 to be taken at an early stage, as the plant grown with distilled water 

 was beginning to die. 

 (Botanical Laboratories, University of London, King's College.) 



